The Dev Team have updated their blog to let the jailbreakers of the world know how to go about jailbreaking iPhone 3.1. It seems as if Apple has really thrown a monkey wrench into jailbreaking the 3.1 software, however, so sit tight as this may be a bit confusing...
First and foremost they have released the PwnageTool 3.1 for Mac OS X that should only be used with the original iPhone and iPhone 3G. Sorry 3GS owners, you'll have to wait. Be sure to heed some of the Dev Teams warnings before attempting to jailbreak your device.
For the full rundown please visit the Dev Teams blog and make sure you fully understand what you are getting yourself into before attempting to jailbreak iPhone 3.1.
If you don't understand it, don't do it, and TiPb takes no responsibility for the outcome either way. Need more? Check out TiPb