I have bought another (got an O2 contract one) iPhone for my other half to use. This iPhone has been unlocked/jailbroken and has got 1.1.4 (4A102) firmware on it. My question is this - can I put firmware 2.0 onto this phone and use my missus' O2 simcard in it legitimately? After reading elsewhere that you can do this with contract phones when you upgrade to a 3G iPhone, can I do this with the phone I have bought off a frien (don't think it was on contract)? TIA for any pointers.