Well my niece got a G4 for her birthday which was bought in US for full price and there for was told its sim free and can be used with any sim outside US but it seems to be locked or something becouse it gets the following messege:
"Only compatible SIM cards from a supported Carrier may be used to activate iPhone. Please insert the Sim card that came with you iPhone or visit a supported Carrier's store to receive a replacement SIM card."
now that sim card seems to be of AT&T company which is in US while im in Israel and i cant seem to contact them becouse im not in US. so i dont rly know what to do, if anyone can help that would be grate.