I've been running my iPhone 3G on 4.0 for awhile now and want to upgrade to the most recent/last available software for this phone, 4.21. I am unlocked and want to make sure I keep my unlock as I'm no longer on the official carrier (even though I finished that contract and hate that there is no official unlock). I keep reading about basebands and iPad flashes and am thoroughly confused. Can I just download the latest redsn0w or pwnage tool and re-jailbrake the phone then download ultrasn0w again? My baseband is 5.13.04. Thanks, much appreciated. Sidenote: I've read I can enable Gamecenter and HDR even though they are not supported on my model, is there any point to HDR as the camera sucks so much on the 3G?