Hello, I have a current family plan with ATT, but I am moving to Australia in about a month for graduate school. I have an iPhone 4 now, not jailbroken or unlocked. I was wondering if I could just bring my iPhone to Australia, go into one of their provider stores (Optus, Telestra, Virgin) and see if they can unlock my phone and then sign a contract with them, and then just use one of their SIMs? Or unlock it before I move, and then go into one of their stores? I also am not too much of a tech wizard, and do not want to damage the phone in any way. I am just really trying to avoid having to sell my iPhone, then buy a new one in Australia because it seems like a hassle...but is it the smartest move? Thank You!