Hi everyone, I'm new to the world of the IPhone so excuse me if the answers to my questions are obvious ones. Basically, I'm moving to Japan in about a week and am lucky enough to be eligible for a phone upgrade with Att, meaning I'd only have to pay about a hundred bucks for a new iphone (It's actually on my brother's account who doesn't care if he needs to sign another two year agreement). So, my question is, if I buy a new iphone here from Att, could I bring it over to Japan and use it with Softbank's service? I already have Softbank service/sim card (thanks to my Japanese gf) so getting a sim wouldn't be a problem, I just wanted to make sure that after I buy the phone, I could just slip the softbank sim card into my iphone and it would work without a hitch. And when I say work, I mean not just phone functionality but apps/internet/all that good stuff as well. Thanks guys!