George Hotz or GeoHotz as he is popularly known has managed to write a software based jailbreak for iPhone OS 3.1.3/3.1.2 which is untethered, aka you will not have to jailbreak your iPhone or iPod Touch if it restarts or the battery runs out.
The Untethered Jailbreak for iPhone OS 3.1.3 has not been released yet, however, GeoHotz has uploaded a video of the working jailbreak on YouTube (embedded below). Apple had made it pretty hard for iPhone jailbreak developers to create untethered jailbreaks and this news will definitely bring a lot of cheer to people who have been waiting for it.
GeoHotz is also the author of blackra1n a jailbreaking tool for iPhone and iPod touch. The new untethered jailbreak will be released as a new software, however, George has said that there is no fixed release date yet.
We will keep you in the loop on when a untethered jailbreak is released by George, in the meantime watch the video of the jailbreak in action below.