Ok, I JB and unlocked my iPhone 4 and am using it on T-Mobile, I go to school in Bloomington, In and AT&T is partnered with IU, meaning students can get a 12% discount, and for all wireless services at the university AT&T is the provider, so as you can see AT&T gets amazing converage, literally everywhere on campus, in bulidings, and in the basement of come classes which is pretty impressive. I have unlimited roaming for the plan I am on, but with NO Data. when I drove from chicago to IU I was roaming on centenial wireless? Is their any setting I am missing on my iPhone that would have roaming turned off? I reset network settings after the car ride so maybe i messed with something? AT&T always gets a signal here and sometimes I get no service, like in a few of my friends dorms. Is their any way to turn on roaming and connect to AT&T, or do you think they will not let anyone roam on their network?? thanks.