Most of the good deals are with companies like Sprint and Nextel that require calls be placed only from their networks. That's great if you're in a city or on the interstate highway system -- but it really bites if you're in a small town or rural area more than a few miles from an interstate, where those companies do not have cell sites.
There are large areas in West Virginia that have no cell service at all. And most of the served parts of the state have access only to carriers that provide none of these great deals. I find it strange when I hear these stories about cell service all over the place in third-world countries -- or of hikers being rescued in remote places in the US thanks to a cell phone. But I can find many places within 150 miles of Washington DC that have absolutely no cell service -- as well as no local (no toll charge) internet access dialup numbers from land lines.
As far as that goes, there are rural areas that don't even have landline service available. I had to string my own landline over a mile from a shed on land I leased next to the highway to be able to get service at my house. And there's absolutely no cell service in this corner of the county. I'm not bitching as it was my choice to get land in a remote area and I can't expect them to have a lot of money-losing cell sites. Just don't believe anyone's claim to nationwide coverage -- there is no such thing as "nationwide" cell service and probably never will be.
Life in Cell -- isn't like the X-File where Fox Mulder is inside a buried steel boxcar at the bottom of a narrow canyon, a hundred miles in the desert in the Four-Corners area of the Southwest placing a call from his 600-mw cellphone.