One of the most frustrating things about a long commute can be going into a subway and losing your phone signal. So an ad like this one can be rather hearkening:
I have T-Mobile and my G1 has been getting better coverage on the Blue Line subway in recent weeks. Unfortunately, this improved coverage doesn't help as much for data usage. T-Mobile's 3G coverage is already relatively slow to begin with and my G1 tends to drop to EDGE speeds in a subway so checking email and web browsing can be slow. On the other hand my Palm Pre tends to lose both voice and data in the subway so T-Mobile is ahead of the game here.