I need some help... I want to sell my iPhone so I want to unlock and jailbreak it. I have 3.0 GM installed currently and am curious how to unlock it... I know about yellowsn0w, is there a way to downgrade my baseband for use? Is 3.0 jailbreakable or do I need to go to 2.2.1? Any help is greatly appreciated and I will pay in thanks.