Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability.

I am a longtime Palm user and am wondering if the new Palm Pre smart phone can run all the Palm OS programs I have become used to on my Treo.

The Pre is a clean break with Palm’s former operating system and previous hardware, and was designed as a platform for a new generation of software programs, or apps. It uses a new operating system called webOS, which wasn’t built to run old Palm OS programs.

However, there is a $30 program called “Classic” by a company called MotionApps (motionapps.com) that emulates the old platform and makes your sleek new Pre look and work like an old Palm device. It is intended to allow older programs to run on the Pre inside this virtual environment created by Classic. I haven’t tested it with older third-party programs and so I can’t say how well they work in this emulation mode.

But there are some caveats to this method. First, not all old Palm programs will run inside the Classic environment, or at least run well. The company lists those certified to work well on its Web site. Second, the old apps can’t activate certain features of the Pre, such as the camera. Third, Classic’s maker says it hasn’t yet figured out how to sync the old apps with a computer using Palm’s old, familiar HotSync process.

Can the Palm Pre be used as a modem for my laptop?

Sprint, the carrier that is launching the Pre, says the answer to this question is no. The company says its data plans for the Pre don’t permit that scenario.

I use Time Machine for my Mac, but I would also like the belt & suspenders security of manually backing up my invaluable iCal data on an external hard drive. How would I do that?

It’s easy. Just go into iCal’s File menu, select “Back up iCal…” and you can save a copy of your calendar to any drive connected to your computer, or even to any computer or external drive on a network, or over the Internet, that your Mac can access. To restore your calendar, just go to the same menu, but this time select “Restore iCal…” and then select your backup file.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I saw your column last week saying Apple’s MobileMe now does a better job of syncing contacts, calendar items and email. But will it allow me to sync to my iPhone directly from my company’s corporate calendar, address books and email?

MobileMe is meant for consumer data, not corporate data. Essentially, Apple’s own servers act like a company’s servers in order to bring corporate-style push syncing to consumer data that isn’t kept on corporate servers. To sync your corporate contacts, calendar items and email to an iPhone, you would use a different built-in option in the iPhone: Microsoft Exchange. Assuming your company’s IT department certifies the iPhone as an acceptable device, and your company uses Exchange, as many or most do, you can use an iPhone to perform instant two-way syncing of corporate contacts, calendar and email. It works just like a BlackBerry or Windows Mobile phone in this scenario. I have tested this, and found it worked well.

Is it possible to sync a Treo or BlackBerry using MobileMe? If not, how can I transfer my Treo contacts and calendar items to the iPhone?

While MobileMe is agnostic when it comes to computer platforms, working on both Windows and Macintosh computers, it is single-minded when it comes to handheld devices. It synchronizes data only to Apple’s own iPhones and iPod Touch devices. It doesn’t work with the Treo, the BlackBerry, or any other smart phone or handheld device beyond those made by Apple. One simple way to move contacts and appointments from Treo to iPhone is to use Outlook as an intermediary. First, sync your Treo to Outlook. Then, just plug your iPhone into your PC, launch iTunes, and sync the iPhone with Outlook. The data from your Treo should then be on the iPhone. MobileMe isn’t required.

I can’t find the location of the files contained in my Personal folders in Outlook that contain my contacts and saved emails. Can you help?

To find the location of the single combined Outlook data file that contains your email, contacts and calendar, follow these steps. First, select “Data File Management” from the File menu. A window will open showing the name of your data file, which includes its location on your hard disk. Click the button to the right that says “Open Folder,” and you will be in the folder that contains this file, with the file’s name or icon highlighted. Outlook data files use the extension “pst” at the ends of their names.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I am a Palm Treo user and would like to get an iPhone for the apps. But I have tried the virtual keyboard on the iPhone in the store and hate it. Is there a stylus you can use for better accuracy, or some software trick?

I don’t know if they improve accuracy, but there are several stylus brands made for the iPhone and iPod Touch. They are aimed at making typing easier, especially if you have long nails or are wearing gloves. One example is the Pogo, a $15 iPhone stylus from a company called Ten One Design, at tenonedesign.com.

In addition, there are several iPhone apps that attempt to help typing accuracy by allowing you to compose emails, text messages and Twitter posts using a wide, landscape keyboard rather than the narrower standard keyboard. You type your message in these apps, and then the app sends them to the iPhone’s email program for transmission. One that I have used is called TouchType. It works with email and Twitter, and costs 99 cents.

Another interesting solution is a free app called ShapeWriter, which lets you type by sliding your finger along a keyboard to connect the letters in words. You never have to lift your finger until you are done with a whole word. Messages you compose in ShapeWriter can be saved as notes or shipped to the email program for sending.

Finally, I should note two things about typing on an iPhone. First, it’s difficult to know if you’ll be comfortable with it from just a few minutes in a store, because it usually takes a few days to master. Second, some people won’t ever find it acceptable, and these folks should choose a phone that has a physical keyboard.

In your review of the new version of the Safari Web browser, you said some Web sites were publishing methods for undoing some of the changes in it that you criticized. Can you explain how I can do that?

There are two methods for changing Safari 4 so it looks and works more like the previous versions, while retaining its faster speed. One method involves typing techie commands into the computer. But, for mainstream users, I recommend another: downloading a new free utility called Safari 4 Buddy. It’s available at swoon.net/site/software.html.

Safari 4 Buddy allows you to just check off buttons that can change the placement of tabs in Safari 4 so they’re under the toolbars, rather than at the top of the screen, and restore the blue page-loading progress bar that Apple killed. It also permits users to change other settings Apple omitted from the browser’s Preferences menus. I have tested it and it works.

However, this utility works only on the Mac version of Safari 4. I don’t know of any way to make these changes in the Windows version. Also, there’s no guarantee that Apple won’t make future modifications to the browser that might reverse any customizations Safari 4 Buddy makes.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I bought an iPhone and was frustrated that my fingers appear to be too large to type properly on its virtual keyboard. Is there a stylus that works with the iPhone?

I hadn’t realized this until recently, when a friend who bought one showed it to me, but, yes, there is. The iPhone wasn’t designed to operate with a stylus, and the small, thin, hard kind that one uses with, say, a Treo, doesn’t work right with the iPhone. But there are some companies that sell a wider type of stylus with a soft tip that approximates a small fingertip, and is designed for the iPhone.

If you type “iPhone stylus” into a search engine, or an online store like Amazon.com, you will see a number of inexpensive choices. One downside: the iPhone doesn’t have a built-in slot for a stylus. My friend carries his, which has a clip on the end, like a pen, in his pocket.

I just purchased an external hard drive for my PC that connects through a USB port to back up photos and important files in the event of a computer crash. Would this hard drive be affected if my main hard drive crashed? Should I disconnect the external drive when it’s not in use?

The two hard disks are separate devices, and if one has a mechanical failure, it doesn’t affect the other. There might be some scenarios in which a problem with the computer itself, as opposed to a breakdown of its internal hard disk, could affect the external drive. And malicious software could corrupt or erase files on the external drive. An electrical surge could also affect both drives, or fry the computer itself.

Many people can’t disconnect their external drives, because they use automated backup programs, or frequently save files to the drives. If you are doing only occasional manual backups, you could disconnect the extra drive when not in use, so you’d feel more comfortable. But, for maximum peace of mind in case of an electrical surge, you should disconnect it not only from the PC, but from the electrical outlet as well, even if you are using a surge protector.

You can find Mossberg’s Mailbox and my other columns online free at the All Things Digital Web site, http://walt.allthingsd.com.

Write to Walter S. Mossberg at mossberg@wsj.com

I am considering the purchase of the MacBook Air (AAPL). If this computer freezes up, as my current Dell Inspiron does on occasion, how would I correct for that? I usually remove and then replace the battery on the Dell (DELL). But what would I do if this happens with the Air, since it has no removable battery?

You can force a frozen MacBook Air — or any current Mac laptop — to shut down and restart without removing its battery. You just hold down the power button for a few seconds until the machine shuts off, then wait a few seconds, then turn it on again.

I am a Verizon (VZ) customer and have a Palm (PALM) Treo 700W for personal use. I would like to replace the Treo but, in light of Verizon’s announced “open network” policy, I am wondering if this is the right time.

It’s far too early to know what new phones will be available under the new Verizon program, since that depends on which phone makers decide to make devices to run on the “open” network, and what kinds of devices they might produce. There is the potential for phones that are more creative or interesting than what is available today, but it’s only a potential. Verizon has just laid out the first details of the plan, and no product announcements are likely for quite a while. If your Treo needs replacing soon, and you want to remain a Verizon customer, you will have to choose from the company’s current smart-phone offerings.

Are there any cellphones that allow for two separate phone numbers? Right now I carry two devices, both with the same carrier.

At least in the U.S., each cellphone, or each SIM card that goes in a phone, is normally tied to a single number. To use two numbers on a single phone, you could purchase an unlocked phone running on a GSM network and then purchase two SIM cards, each with a separate number, and swap them in and out. But that would be an inconvenient process, since inserting and removing SIM cards typically requires opening the phone and even removing the battery.

You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I currently spend about $50 to $60 per year for Norton Security software. Is this necessary when Windows XP has its own security built into the operating system?

Windows XP doesn’t include antivirus or antispyware programs, so you definitely need some sort of add-on security software. If you don’t want to pay for it, there are free alternatives available.

How do we determine when to purchase a new PC? Our current Dell is about five years old. I’m feeling a little worried because I have my music and photos on the computer and don’t want to lose them.

There’s no universal answer to your question. In general, I don’t believe people should replace computers that are working well for them just because they reach a certain age. On the other hand, five years is pretty old for a PC. At that age, the odds increase that the hard disk may develop problems, and that newer versions of the software you like will require hardware upgrades that may cost more than you want to invest in an older machine.

Assuming your Dell is working fine, that you aren’t a power user, and that your music and photo activities are simple and basic, there’s probably no urgent need to replace the PC. But, to assuage your concern about “losing” your pictures and music, you might back up those precious files to an external hard disk or an online backup service.

Last week, you compared the start-up time of Windows Vista to Apple’s new Leopard operating system, and found Vista to be much slower. But you used different laptops for each. What would the numbers be on the same Macintosh running the two operating systems?

I ran the tests again on a single computer, a fairly new Apple iMac, which can be started up, and restarted, in either Vista or Leopard. I used the Mac’s Boot Camp feature, in which only one operating system is running at a time, has its own dedicated portion of the hard disk and fully controls the hardware. The machine uses an Intel processor and other key components commonly found on Windows machines, and runs Windows just like a Dell or any standard Windows PC, without any involvement from the Mac operating system.

This Vista installation doesn’t include any of the speed-robbing trial software commonly included by PC makers, though it does have security software from Symantec. However, the test results were very similar — Leopard started and restarted much more quickly than Vista did.

In this simple test, I timed both operating systems from a cold start and a restart until the computer was fully ready for operation, with the hard disk quiet and the network connection established. The cold start, beginning with the computer completely off, took Leopard 46 seconds, but took Vista one minute and 42 seconds. A restart, beginning with the computer running an email program, the Firefox Web browser, and Microsoft Word, took one minute and two seconds for Leopard, and three minutes and 17 seconds for Vista.

You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital Web site, http://walt.allthingsd.com.

Write to Walter S. Mossberg at mossberg@wsj.com

Q. Is there any way to watch high-definition TV on a Mac in real time — not downloaded from a service?

A. As on Windows computers, there are add-on TV tuners for Macs that can both receive and record TV programs in real time. Some of them can handle high-definition programming. The best-known company that sells such tuners for the Mac is called Elgato, at elgato.com.

Q. I’m interested in your perception of the Treo’s future. I currently use (and generally like) a Treo 650. I’d like to upgrade, but I’ve read recently that Palm’s future is uncertain. I wonder if you think the Treo is on a slippery slope down, while the Apple iPhone will likely improve.

A. I do believe that Palm has allowed its software to stagnate and hasn’t moved fast enough to make its hardware thinner and cheaper. However, there are also some positive signs at Palm. Its new Centro phone is pretty good, smaller and less costly than a Treo. And the company is receiving an influx of funds and talent from a group of outside investors with experience at Apple, among other places.

Palm’s fate and future may depend on the success of a project it has undertaken to create an entirely new operating system. But the outcome of that effort won’t be known for quite some time.

The iPhone, which is already very good, will likely get better, as it is just at the beginning of its life. It has raised the bar for other smart-phone makers, such as Palm, especially when it comes to software. But I expect other companies to match at least some of the iPhone’s features and style, which means Apple will have to hustle to keep its lead. In the past five years, Apple has done very well at staying ahead of competitors in the design of its computers and portable music players. But the cellphone business is full of companies with more imagination than the typical PC maker and more resources than many makers of portable music players, so the challenge for Apple will be greater.

Q. My mom is legally blind and has difficulty working with email and downloading files. I try to help her by phone, but it never works, and we live far apart, so I can’t just go over to help her. I would like to install an application on her PC where I can take over remotely from home. Do you have any suggestions for this type of application?

A. There are a number of possibilities. One very simple option is a program called CrossLoop, at crossloop.com. Some versions of Windows, such as Windows XP Professional and Windows Vista Ultimate, also have remote desktop control built in.

You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital Web site, http://walt.allthingsd.com.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about PDAs, Microsoft Office 2003’s compatibility with Vista, and memory upgrades for a MacBook Pro.

My wife has requested that we get her first “PDA” and asked me for my advice on which product to buy. I am unfamiliar with the comparative features and function of BlackBerry and Treo. What would you suggest?

Well, first of all, both of these products are primarily communication devices — they make phone calls and fetch email, in addition to performing the functions of a Personal Digital Assistant. So, if she really just needs a PDA, I’d avoid both of them and get a cheaper Palm PDA that isn’t a phone or email device. The $99 Z22 would do the trick, and, unlike a phone, it requires no monthly fee. However, if she wants a phone-and-email device that is also a very good PDA, the Treo beats the BlackBerry hands down. The latter is first and foremost an email device and now has a decent phone. But its calendar, address book and other PDA functions are weak. The Treo, which evolved from the Palm PDAs, is much better at these tasks, in my opinion, especially for personal, as opposed to corporate, use.

Your columns helped me select a new laptop today that should be able to run Vista Ultimate. However, although two of your columns report that Microsoft Office 2003 should run on Vista, two salesmen at Dell said it wouldn’t. Who’s correct?

A: I am, and it’s sad and troubling that Dell personnel would give out such patently wrong information. One might even suspect they were trying to sell you the newer version of Office when you don’t need it. I have personally tested Office 2003 on a Vista computer, and it runs fine. But, just to make sure, I forwarded your question to a senior person at Microsoft and he replied that the Dell people you spoke to are: “misinformed at the least.” He confirmed that Vista supports both Office XP and Office 2003 (as long as they have been kept up to date with the latest service packs) as well as the new Office 2007. One possible explanation is that the Dell folks you spoke to misunderstood your question. Dell and other companies have ceased selling Office 2003, or will soon stop doing so. Therefore, it’s possible that they were under the impression that you were seeking to buy it, rather than merely to install and run a copy you already owned. But Office 2003 is compatible with Vista.

I own an Apple MacBook Pro laptop that came with 512 megabytes of memory. I am going to upgrade to either one gigabyte or two gigabytes. I am not a gamer. Do I really need two gigabytes for running applications or will one gigabyte suffice? The biggest application I use is Final Cut Studio.

In general, one gigabyte is all a MacBook Pro needs for doing common tasks such as email and Web browsing, word processing, music playback and simple photo and video editing with built-in programs like iPhoto and iMovie. However, Final Cut Studio is a massive video-production program meant for professionals, and it demands lots of memory. In fact, Apple’s Web site for the latest version of the product suggests between two gigabytes and four gigabytes, depending on the content you expect to edit and produce. So I would go with two gigabytes, or even more if your model of the MacBook Pro can handle it. In fact, if you are more of an amateur, I’d consider the lighter-duty Final Cut Express, which Apple says does fine with one gigabyte and can handle high-definition content with two gigabytes.

Write to Walter S. Mossberg at mossberg@wsj.com

This week, I was swamped with questions about Apple’s hot new iPhone, so this is a special all-iPhone edition of Mossberg’s Mailbox.

Can you physically remove the included AT&T SIM card from the iPhone and replace it with another AT&T card or one from another wireless carrier?

Yes, and no. The SIM card, which carries the iPhone’s account information, can be removed by inserting a paper clip into a tiny hole at the top of the phone. However, Apple says that if you replace the included card with one from another carrier, like T-Mobile in the U.S., or Orange in Europe, the phone won’t work. According to Apple, some non-iPhone AT&T cards may work, but some may not.

It’s possible that hackers will figure out a way to override this lock on other carriers’ SIM cards. But, as of now, the iPhone will work only with AT&T. Even overseas, at least until Apple does deals with foreign partners, you won’t be able to use SIM cards from other carriers. The iPhone will work overseas, but you will have to roam with AT&T and pay high charges. For instance, according to an AT&T spokesman, if you make a call in Europe, it would cost $1.29 a minute. It would cost 99 cents a minute if you are on one of AT&T’s $5.99 per month international plans.

Since the iPhone battery is sealed in and can’t be easily replaced by the user, what happens when it dies? Will you have to buy a new iPhone?

No, but you will have to send the phone to Apple, or drop it off at an Apple store, to have the battery replaced. The battery is covered during the phone’s one-year warranty period. After that, replacing the battery costs $79, plus $6.95 for shipping, and takes three business days. Details are at apple.com/support/iphone/service/battery/. Some small companies may eventually offer to do this for less, or in less time, as they have for the iPod.

One twist: because a phone is a necessity, Apple is offering loaner iPhones for $29 while your phone’s battery is being replaced, or for the period of any other repair on the iPhone. You will have to switch the AT&T SIM card from your own phone to the loaner, and then back again. Details are at apple.com/support/iphone/service/faq.

In addition, Apple warns that all the data on your iPhone will be wiped out during a battery replacement, but notes that it can easily be restored by simply syncing again with the iTunes software on your computer once you get it back with a fresh battery. That’s because, whenever you sync your iPhone with iTunes, it backs up the data on the phone. You can also use this method to fill your loaner iPhone with your own data.

Can I use the iPhone via a Bluetooth wireless connection in my car? Can I use Bluetooth to transfer files or other information between the iPhone and a computer?

In my two-week test of the iPhone, I succeeded in connecting it without much trouble to the built-in audio system and microphone on a friend’s BMW. Almost instantly, the over 700 contacts I had on my test iPhone were displayed on the car’s dashboard screen and calls could be made and received through the iPhone.

However, this first iPhone can use Bluetooth to connect only with cars and with wireless phone headsets. It cannot use Bluetooth to transfer any data to or from a computer, to play music through stereo wireless headsets, or for any other purpose. As with many other missing features, Apple has the ability to add these to the iPhone through software updates delivered by synchronizing with your computer.

If the iPhone’s Web browser is so good, why can’t it play video on Web sites I visit?

At launch, the iPhone version of the Safari browser is missing some plug-ins needed for playing common types of Web videos. The most important of these is the plug-in for Adobe’s Flash technology. Apple says it plans to add that plug-in through an early software update, which I am guessing will occur within the next couple of months. However, a separate program included on the iPhone can play a limited selection of videos from YouTube, and the phone can play videos you purchase from Apple’s iTunes store, and certain videos you create yourself.

You have been critical in the past of some smartphones that don’t allow you to delete emails with a single click. Can the iPhone do this?

Yes. If you are reading an email and want to delete it, you just tap on a trash can icon at the bottom of the screen and the message disappears into the trash can with an animation that resembles water being poured through a funnel.

However, in the iPhone email program’s list view, it takes two steps to delete an email. You have to swipe across the message header or preview with your finger, and then tap the red delete button that appears. You can also press an “Edit” button, which allows you to delete emails in the list view, but this still requires two taps per message.

Unlike on a BlackBerry or Treo, the iPhone doesn’t allow you to delete whole groups of email en masse by date, or even to select large groups and then delete them en masse. This would be a good feature for Apple to add down the line.

Can you buy an iPhone and just use it to play music and videos like an iPod, and to surf the Web or get email over Wi-Fi, without signing up for an AT&T service contract?

No. None of the iPhone’s functions, except calling 911, will work unless the phone is covered by a two-year AT&T service contract, and has been “activated” by AT&T. That will cost you $60 a month at a minimum. If you are thinking of buying an iPhone, you should plan on being an AT&T customer, and if AT&T coverage is poor where you live, work and travel frequently, I advise you NOT to buy an iPhone.

You and many others have criticized AT&T’s EDGE data network, which the iPhone uses, as slow. You have noted that AT&T has a much faster data network. Can the iPhone be upgraded to use that faster network?

No, it can’t. This first edition of the iPhone can’t use any cellular network faster than EDGE, which is much, much slower than the fastest cellphone data networks available from AT&T, Verizon or Sprint. It can, however, use very fast Wi-Fi wireless networks, when you are in range of them.

Apple hasn’t said anything about future iPhone models, but I fully expect a future model that can use these faster cellular networks, which are usually called 3G networks. So, if this is very important to you, I’d suggest waiting to see if such an iPhone emerges. But I don’t expect this to happen anytime soon.

In the past few days, AT&T seems to have tweaked its EDGE network, at least in some locations, so it runs faster than it has in the past. In my own speed tests, around Washington, D.C., I have seen repeated speeds of around 150 kilobits per second, roughly 50% better than the 100 kbps I have seen with EDGE in the past. However, I have also recorded speeds as slow as 82 kbps. And, even the new, faster speeds are way below those of the faster American cellular data networks, which can easily reach 500 to 800 kbps on a phone.

How good is the iPhone’s To-Do list or Task function?

Awful — in the sense that it doesn’t exist. The phone does have a calendar, of course, which syncs with the most popular calendar programs on Windows and Macintosh computers. And it has a Notepad, which doesn’t sync with any program on any computer (though you can email notes to yourself and others). But it has no To-Do list function at all.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about printing wirelessly from a digital camera, Intel processors, and playing iTunes songs on a Treo.

Is there a way to print wirelessly from a digital camera to a printer?

Yes. A number of digital cameras include Bluetooth, and a few even have Wi-Fi. These wireless technologies allow you to send your pictures to a wireless-equipped printer, over varying distances. In some cases, you can also use this wireless capability to transfer the pictures in the camera to a computer, without the use of cables or the need to remove the memory card.

I am a high-school student and am buying a Dell laptop for use during a semester in Israel. I plan to use the computer only for word processing, watching videos, listening to music, viewing pictures and using the Internet (no gaming whatsoever). Does it matter whether I get Intel’s Core Duo, or Core 2 Duo processors? Also, would you recommend purchasing 1 or 2 gigabytes of memory?

Assuming you are on a budget, I would suggest the Core Duo, since the extra speed and power of the Core 2 Duo won’t make any significant difference in the kinds of tasks you will be performing. However, I would advise spending extra for 2 gigabytes of memory if the computer comes equipped with the new Windows Vista operating system. If you opt for the older Windows XP operating system (assuming it’s available on the model you choose) you will be giving up some degree of security, but you can also get away with just 1 gigabyte of memory.

Is there a way to “authorize” the copy-protected songs I bought from iTunes so they play on a Treo 700wx? Are there any cellphones that can play these songs?

No, you can’t directly play copy-protected songs you have purchased from iTunes on a Treo, because Apple hasn’t licensed the decoding software to Palm, which makes the Treo. The only way to make them playable on your Treo is via a laborious work-around, in which you burn the songs to CDs on your computer, then reimport them as nonprotected MP3 music files and manually input the artist and title data. After that, you could move them to the Treo and play them.

There are only a few cellphones that can directly play copy-protected music purchased from iTunes. One is the new iPhone, which comes out tomorrow from Apple itself, and contains a full-blown iPod that can hold more than 1,000 songs. The others are a handful of Motorola models, which contain a version of iTunes that can hold and play back up to 100 copy-protected songs.

Write to Walter S. Mossberg at mossberg@wsj.com