I have this iPhone 4 bought from Japan , iOS 5.1 with firmware 04.12.01..it is been locked, Now I am looking for a credible answers which can help me unlock my iphone. I already went thru surfing various websites catering unlocking of iPhone units but unfortunately no one offers unlocking units which came from Japan . I also heard from friends regarding "GEVEY SIM ". Is it possible to use this one.? I need your suggestions guys . And also I am looking for answers on how can I unlock my I phone..Thanks a lot!!