In your review of the new iPhone 3GS, you said that AT&T had changed its upgrade policy so some buyers of the previous model could get the new-customer price earlier than planned. Can you explain this in more detail?

Almost all cellphones in the U.S. are subsidized by the carriers to bring down prices. Typically, existing customers—who have already benefited from a subsidy—can’t upgrade at the lower new-customer price (in this case $199) until they reach a point in their contracts where this subsidy has been recovered. These dates vary, based on a formula that takes into account things like the customer’s monthly spending rate.

When some early adopters of the 2008 iPhone model, the 3G, discovered they wouldn’t immediately qualify for this $199 “standard upgrade” price—the same as the new-customer price—they got angry. So AT&T made a concession, but only a partial one. It declared that any customer who had been told he or she couldn’t get the $199 price until sometime in July, August or September of 2009 would in fact now be able to qualify for that lower price starting on the first day of availability.

This concession doesn’t apply at all to owners of the original 2007 iPhone, or even every owner of the 2008 3G model. And it isn’t based on when you bought your 3G, but when the system told you that you could buy the new model at the “standard” upgrade price of $199. You can check the price AT&T or Apple will charge you for an upgrade by going to www.att.com/iPhone and clicking on “Check upgrade eligibility.”

I’ve recently heard that the new Palm Pre smart phone is unable to import data from the old Palm Desktop program. In other words, if you have Palm Desktop filled with data from a previous Palm model, you’ll be unable to get that data into your new Palm Pre. Is this true?

No. While the Pre isn’t designed to repeatedly sync with the old Palm Desktop software, Palm does offer a program, for Windows and Mac, that will perform a one-time import of your old data from Palm Desktop. It can also do a one-time import of data from certain other desktop programs as well, including Microsoft Outlook on Windows, and iCal and Address Book on the Mac. This program will help you move your data to one of the online services, such as Google, with which the Pre is designed to sync continuously. The software is called the Palm Data Transfer Assistant and is free at http://bit.ly/3lIaZ.

I am contemplating purchasing the 17” MacBook Pro rather than the 13” or 15” models because the antiglare matte screen is offered only with the 17”. How bad is the glare on the smaller screens and how cumbersome do you find the larger 17” MacBook Pro?

For a laptop of its size, the 17” MacBook Pro is remarkably thin and light. But I did find it cumbersome to use in coach seats on airplanes and to cram into small briefcases. As for the glossy screens, which are now the most common option on many laptops, they bothered me at first, but I don’t notice the glare now. However, both of these are personal issues. So my suggestion is to go to a store and see for yourself.

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

I am utterly fascinated with the iPhone. Dying to get one. I’ve been a Verizon Wireless person for 15 years and have never had a coverage problem in the metro Boston area. I don’t hear great things about AT&T’s 3G. Do you think it’s worth the switch?

While I believe the iPhone is a marvelous device, I have always advised that nobody should get any phone unless it is on a network that they are sure works to their satisfaction in the areas where they will use it. Personally, I find AT&T’s network adequate where I use it, and getting better, so I am happy with my iPhone. But there are many others who have either given up their iPhones out of frustration with AT&T, or who have decided against buying one because they prefer another carrier, or want to avoid AT&T.

So, my advice is to ask friends around Boston who have iPhones or other AT&T 3G devices how they feel about the network. You might also enter your ZIP Code at some Web sites that track overall carrier coverage and dead zones, like cellreception.com, or deadcellzones.com.

If this research suggests you should avoid AT&T, but you are still “dying” for an iPhone, you might consider the iPod Touch, which is essentially an iPhone without the cellphone inside. It lacks the iPhone’s camera, GPS and built-in microphone, but it does connect to the Internet via Wi-Fi and runs the vast majority of iPhone apps. It doesn’t carry any monthly fee or require a carrier contract.

How do I forward an email from Gmail? I don’t see any icon for forwarding messages like I do on other email programs.

Gmail hides a bunch of menu choices under the Reply icon in the upper-right-hand corner of open emails. If you click on the small downward arrow next to the Reply icon, you will see more actions you can take on the message, including Forward, Reply to All, Print and others.

I read your recent article on IE8 and installed it on my desktop. I did not notice in your article any mention of IE8 slowing the computer down significantly, but it has had this effect on my PC. Why didn’t you mention it? Can I uninstall IE8 and return to the prior version?

I didn’t mention the problem you are having because I never observed that Internet Explorer 8 caused any general slowdown of any of the multiple Windows PCs on which I tested it. I did warn that IE8 itself grew sluggish when it had a large number of Web sites open simultaneously in tabs, but, in my tests, even that didn’t slow down the whole computer.

However, you can indeed uninstall IE8 and return to the previous version. Microsoft has provided complete instructions, and even an automated uninstall program, at: support.microsoft.com/kb/957700.

• 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.

At work I am told to turn off my desktop PC at the end of the day. My wife’s office tells her to leave her computer on overnight. My former employer said to turn off the monitor but leave the PC on. What’s right?

Given the energy, environmental and economic crises, my view is that you should completely shut down both your computer and your monitor any time they will be unused for more than a few hours. And, of course, you should set them to go into sleep mode after they are idle for far less time than that. To be honest, I myself am not always faithful to that advice, but I am resolved to get better at it.

Of course, there are some nuances to the issue of overnight shutdowns. If you, or your company, routinely perform important operations overnight, like backups or security scans or system tune-ups, then you have to leave the computer on, but you should still turn off the monitor.

How much memory do you recommend for a new computer running Vista Home Premium?

Two gigabytes minimum, and three gigabytes if your budget can handle it. The latter is roughly the maximum that popular consumer versions of Vista (called 32-bit versions) can use.

For smooth, quick operation in common tasks, it’s been my experience that Vista demands more memory than either Windows XP or Apple’s Leopard operating system. And the need for added memory rises if your PC uses “shared” video memory, which means your graphics system lacks its own dedicated memory and relies on draining the main memory. This arrangement is common in less expensive computers.

We are planning a trip to the British Isles this summer with a side trip to Brussels. We plan to bring our iPhone on the trip. What is the current situation with using European networks? Will my U.S. AT&T account just work or do I need to make pre-arrangements? I realize my iPhone won’t be able to access the faster 3G networks over there, but can I use slower networks? Being limited to Wi-Fi would be a bummer.

The iPhone 3G can indeed handle 3G networks in Europe, though the original iPhone can handle only slower networks. Both models can use Wi-Fi there.

You will need to call AT&T before you leave, though, and “provision,” or set up, your account, for international roaming. Note that such roaming is expensive, with very high rates for both voice use and data use. AT&T has some monthly add-on plans that cut these fees, but, if I were you, I would turn off data roaming until and unless I needed it; do most email and Web surfing via Wi-Fi; and consider downloading Truphone, a voice-calling program that uses Wi-Fi instead of cellphone networks.

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.

You recently wrote that people should make sure new laptops have the new, faster “n” version of Wi-Fi built in. But how do you do that? All I see are impenetrable feature descriptions such as: “Built-in high-speed wireless LAN (802.11b/g).” I cannot understand this language.

Computer retailers too often insist on using techno-babble or engineering lingo, even when referring to frequently used terms like “Wi-Fi.” In my view, this practice is either lazy, or arrogant, or deliberately designed to confuse.

In this case, the product description you quote in your question is indeed referring to Wi-Fi when it uses the phrases “wireless LAN” and “802.11b/g.” The phrase “LAN” means “local area network,” a means for connecting computers to each other, and to the Internet. Engineers refer to Wi-Fi as “802.11″ followed by a letter like “b” or “g” or “a” or “n.” These letters refer to various flavors of Wi-Fi that have different speeds and ranges. The laptop whose description you quote doesn’t offer the “n” type of Wi-Fi, only the older “b” and “g” types.

In your column about the new Gogo service for using Wi-Fi on airplanes, you mentioned that iPhones will work with the system. But how can one do this legally, when passengers must turn off the cellular radio on phones aboard planes, and the method for doing that on iPhones also turns off the Wi-Fi function?

The solution is to use the new iPhone (AAPL) operating system version due out July 11. This version allows you to turn off the cellphone radio, while leaving the Wi-Fi radio on. It will come on all of the new 3G iPhones, and will be a free upgrade for the original iPhone models. Of course, on flights without officially approved Wi-Fi, both types of radios must be turned off on all devices.

Your June 26 Mossberg’s Mailbox explained how to export Internet Explorer (MSFT) Favorites. Please explain how to export Firefox 3.0 Bookmarks.

You go to the Bookmarks menu and select “Organize Bookmarks.” In the window that opens, select the star icon at the top and choose either “Backup” or “Export HTML.” The first choice saves your bookmarks in a new format introduced in Firefox 3.0 that preserves tags you may have added to your bookmarks. The second choice has been in prior versions of Firefox and will save your bookmarks in the same sort of format Firefox has previously used.

The file created by the “Backup” method can be imported into another copy of Firefox 3.0 by following the same steps, but choosing “Restore” and then “Choose File.” The file created by the “Export HTML” method can be imported into any version of Firefox using the Import or “Import HTML” function.

• 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.