Where does your cell phone work?

Computerworld - While outfits such as Traq-wireless Inc. and LetsTalk.com believe they have developed systems to help hold down cellular phone costs, executives at both companies acknowledge that they can't help solve one of the most frustrating problems of the mobile age: determining where in the country or even within a particular city a cell phone will work.
That's a task that's left to each of the approximately 137 million cell phone subscribers in the U.S. It's a rather thankless one, too, with few resources even in this age of Google to help pinpoint the coverage of any of the major cellular carriers.
The easiest way to determine whether your carrier covers the area you're in is to turn it on and see if you get a signal. But what if you're taking a multistate, cross-country business trip and want to know if your phone will work in six or seven different urban, suburban or rural locations?
Most of the major carriers provide reasonably good coverage of the top 50 cities and their nearby suburbs because the carriers built their cell towers to serve the largest possible customer base.
But forget about coverage in much of rural America. Cell carriers put up towers to serve people, not cows.
To cater to travelers, the major carriers have also tried to blanket the interstate highway system -- but don't expect coverage if you wander far off the interstate. Sprint PCS Group provides excellent coverage of I-95 from Washington to Richmond, Va., but don't expect to access the company's network from the U.S. Marine base in Quantico, Va. The highway is close enough to Quantico for observers to hear the traffic from the base, but Quantico is too far from the Sprint PCS tower to make a call.
You can avoid getting stuck without coverage in problem areas such as Quantico by checking out the coverage maps the cell carriers maintain on their Web sites. However, these maps are so broadly drawn and cover such wide geographic areas that using them to home in on a small town -- let alone a neighborhood in an urban area -- offers as much precision as trying to locate the same town on the kind of globe found in an elementary school classroom.
Finding carrier coverage maps can require a lot of point-and-clicks on a Web site. To access the coverage map on the Web site of Redmond, Wash.-based AT&T Wireless Services Inc., you first have to click the "Shop" button, which then pops up a Web page