As others have said, I hope the practice of locking phones to carriers goes the way of the two-year contract in the U.S. soon. It really is a foolish practice. Why does AT&T care if I use another carrier's SIM card in a phone I bought from them and am still making the agreed upon monthly payments on? They'll gladly keep charging me for their service every month until I call them and cancel the service regardless of whether or not I actually have one of their SIM cards in the phone.