I recently bought a iPhone 3GS running iOS 5.1 and baseband 5.16.05. I already have a 4S on AT&T and want to use this 3GS overseas. I've seen some trickery of flashing an iPad 6.15 baseband onto the 3GS then unlocking with ultrasnow, is this the best way? Now AT&T is announcing unlocking for out of contract phones, which this is. Can i go that route? Sounds simple and perminant, even after software upgrades. I'm planning to just pop in my 4S sim with an adapter and use on occasion, then probably sell. I don't have to add this 3GS to my account to get it unlocked do I? What is the best method to unlock this? Thanks!