GeoHot has just released a new video which shows his new hack in action. It's called Blacksn0w and is able to unlock the new baseband 05.11.07 of the iPhone 3G and iPhone 3GS.
This new baseband appeared in firmware 3.1. So all users who own locked iPhone can unlock it and use with any cellular provider. Users who have upgraded to firmware 3.1 or 3.1.2 by mistake can also use blacksn0w.