Cingular has impressive coverage across the U.S., particularly in the eastern half. That doesn't mean that it has complete coverage or that it offers the best coverage in some areas. As with any choice of a mobile carrier, you need to be sure that you'll have coverage where you live, work and regularly travel.

This may not be an issue for people who live in large cities, but for many, the extent and quality of Cingular's coverage in outlying (and even some urban) areas could be a major consideration. If you're thinking of switching to Cingular for the iPhone, maker sure that you will have coverage where you need it. You don't want to switch carriers and spend the money on an iPhone only to discover that your back yard or part of your route to work is a dead zone or has spotty reception.

3. Is 2G data coverage enough?

One of the big criticisms of the iPhone is that it will only support 2G data service. Apple has said this is to provide the broadest level of coverage until 3G service is more available throughout the country. While that is laudable, consider whether the 2G/EDGE service provides speeds fast enough for your Internet and data needs. (Most users equate 2G data access as similar to or slightly better than dial-up, which is fine for limited Web browsing and e-mail, but not for anything more intensive.) The iPhone's Wi-Fi access may mitigate this, but only if there is an available Wi-Fi network or hot spot.

Also, keep in mind that you will probably be using your iPhone for some time, even if a newer, 3G model is released. So remember to think both about your current needs and your needs over the next couple of years. If you're looking for better coverage, you might want to consider waiting to buy an iPhone until 3G data is included.