I have had AT&T for the past 2 years, and they have been alright. I've upgraded to the GMS and it's better than digital. The only problem is that you can't get a signal in the classrooms and some of the study rooms, but I've learned to deal with it. AT&T has also been purchased by Cingular recently, and people who have Cingular are able to use their phones in the classrooms, so you may be able to use AT&T phones on the Cingular networks when they get the details figured out. I think that most people have Verizon, and they are able to use their phones for the most part all over the school.