Minutes after we showed you how to jailbreak iOS 4 on an iPhone 3Gs using PwnageTool, MuscleNerd confirmed that redsn0w 0.9.5 beta 4 can jailbreak iOS 4 GM running on iPhone 3G. The only thing is that, if you need to unlock your iPhone, you are out of luck. Not that you can’t use the tool to jailbreak, but if you want to try it, you will need to upgrade your iOS which upgrades your baseband and you will loose your unlock ability.
Bottom line: if you need to unlock your iPhone DO NOT use redsn0w to jailbreak iOS 4 GM. If you want to try it, see our tutorial to learn how to use redsn0w…