blackra1n is an upcoming iPhone jailbreak tool for iPhone OS 3.1 to be released soon by purplera1n developer Geohot. GeoHot has found an exploit to jailbreak all iPhones and iPod touches running OS 3.1 and iPhone OS 3.1.2. He has posted the jailbroken iPod Touch 3rd Generation screenshot on his blog.
Sometime back Apple released iPhone OS 3.1.2 to fix issues like network service disruption, waking from sleep, and crashing during video streaming. But the update does not block the exploit GeoHot is using to jailbreak iPhones and iPod touches running OS 3.1 using blackra1n.
The tool was expected to be released today but he is busy in writing a ramdisk side kernel patcher. And trying to find out how to use itunes usb as posted on twitter.