blackra1n : Jailbreak iphone 3.1.2
If you are on the 3.1.2 firmware and want to Jailbreak your iphone, than here is a great tutorial By Technobuzz.net team. But this One is Only Jailbreak not the Unlock. So Unlockers Don,t try this on your iPhone.
WARNING: GeoHot
jailbreak supports 3.1.2 do not update if you are on iPhone OS 3.0.1 or 3.0. Warning 3g and 3gs unlockers, do not upgrade to 3.1.2 using iTunes if you want to keep your unlock. Baseband cannot be downgraded. This one is Only Jailbreak not the Unlock. It worked on iphone 2G, 3G, 3GS.