iPhone Dev Team has just released their latest PwnageTool 3.1.4 tool to jail break your iPhone. The PwnageTool 3.1.4 supports iPhone OS 3.1.2 and can be used on iPhone 2G/3G/3GS and iPod Touch 1G/2G. iPod Touch 3G is not supported at the moment. Read more on the instruction over at their blog.

This release allows your baseband to remain unlocked at 3.1.2, but it does not unlock a new baseband put there by restoring to official 3.1.x. It is super important that people who need the unlock to understand they can keep it only by starting at 3.0 (or earlier) and updating solely to custom IPSWs that don’t update the baseband. For those who have been onboard the “unlock train”, simply install ultrasn0w via Cydia once you’ve restored to your custom IPSW. Don’t forget to turn off the “3G” setting in Settings->General->Network if you use T-Mobile in the U.S.A.