The jailbreakers have managed to keep their speed record intact. Just one day after Apple releases an update to the iPhone OS 3.0 beta, QuickPwn updates its wares to support the new firmware. According to the related writeup, it should work with all iPhone / iPod touch models. After going through the jailbreaking process, you'll need to open icy and follow a few more steps to finish the job. As usual, download at your own risk, and for now, crack is for Windows users only.
Update: The Dev Team has chimed in with the usual list of caveats and warnings. If nothing else, you've now got tacit verification that this release of QuickPwn isn't some malicious hack.