Basically my issue is thus...

I currently have a pay monthly contract with Orange that doesn't end until May 2010 and unfortunately my current phone appears to be on its last legs.

I have family in America and I have considered asking them to pick me up an iPhone (because they're immensely cheaper over there) and send it to me (in the UK) and I'll repay them. The idea then would be to unlock the phone and use my Orange SIM card.

Would this work?