Hi guys! So I got my AT&T iPhone 4S today. Lo and behold though, that recently AT&T dropped ST as a MVNO over the Bring Your Own Phone program (Or so i've heard. Because No wal-mart anywhere around me stocks the ST AT&T Micro SIMs anymore. And the only ones I can find are on Amazon for about $70+) Anyway. Since the iPhone 4S uses the GSM 850, 900, 1800, 1900, and the UMTS/HSDPA/HSUPA 850, 900, 1900, 2100 MHz bands, I was wondering if it would be at all possible to hook my AT&T iPhone up with a ST T-Mobile SIM card, and still have everything working? Because that seems to be the only way I can go. ST only clarifies that GSM phones need to run on the 850 and 1900MHz bands to work on their network, so I imagine it will.