For the Iphone 4, It says to get a "pre-activated micro sim. Does It have to be pre-activated? Couldn't I just buy a att go phone sim card that has already been cut, Then just call att and tell them I just want to activate the sim card, And I don't have a phone, Or can you not do that? Becuase I can't even really Find "pre-activated" sim cards anywhere, And I don't even see why It would need to be pre activated.