OK, I have searched and found this thread: http://forums.macrumors.com/showthread.php?t=970663&highlight=prepaid+sim+iphone4 About cutting a prepaid sim and inserting into the iPhone 4. However some people have had mixed reviews, some work some have said that it doesn't work because the sim card is locked to the phone that it comes with. I have an unlocked iPhone 4, I know it's unlocked because I am on T-Mobile, and it works fine, I can text/make/receive calls with no problem. I moved from Chicago to Bloomington, IN for school and AT&T gets awesome coverage down here. T-Mobile gets good coverage OUTSIDE, but in some buildings, and dorms I get no service at all. However all of my friends on AT&T do. So if I were to buy an AT&T prepaid Sim with $60 unlimited Talk/Text will that work ok with my UNLOCKED iPhone after I trim it. Also can anyone talk about coverage with Prepaid Sim's? I checked coverage for GO Phone/ AT&T wireless And as far as my area they are both the same. However some parts of the Map show AT&T Wireless gets more coverage than Go Phone. So is coverage mostly the same? Any help with either questions is appreciated.