Hi all, I sold my iPhone 2G w/ OS 3.0, which was unlocked to buy HD2. I bought that today, two hours ago, and now returning it because well... it's WinMo 6.5. I just got a 3GS that is unlocked 3.0, and was wondering how do I upgrade it to 3.1.2 and get it unlocked without losing the future capability to upgrade and unlock?