I am planning on unlocking my iPhone 4 soon and getting a pay as you go SIM card since I will be leaving the country, but the only problem is that I have a year left on my contract with AT&T and would rather not pay the early termination fee. A relative has an iPhone 3G which has been in contract for over two years and so could be cancelled. Would it be possible to cancel that contract, take the SIM out of my iPhone and use a MicroSIM to SIM adapter to be able to put it in the 3G, and would this then continue my contract on the 3G without any issues? Could the 3G resume my contract without having to be unlocked and without AT&T knowing my phone has been jailbroken and unlocked after taking the SIM out? I've looked but haven't found an answer to this particular question. Thanks a lot.