I just received a carrier unlock through AT&T for my iPhone 3G. I haven't actually unlocked it YET, though AT&T did send me the unlock code and instructions via email. My question is, can I jailbreak the phone after doing the carrier unlock through iTunes? Are there any precautions or alterations that I must do to the jailbreak process? (And what process/method would you recommend for JB on the 3G?). Any help will be GREATLY appreciated. My iPhone 3G is currently on 4.2.1 (8C148), 05.15.04.