The iPhone Dev-Team wasn't messing around when they promised to release an iPad jailbreak soon after the iPad 3G's release. Today, on their site, they have posted the official release of Spirit. Spirit is the codename for the team's latest endeavor, allowing an untethered jailbreak for Apple's latest and greatest devices.
Spirit is a "userland" jailbreak. This means that it exposes a security weakness in the Apple firmware itself. The jailbreak is applied after the OS kernel is already running, making this weakness something that Apple is sure to patch in a timely manner.
Spirit will work for all devices. The Dev-Team states that the jailbreak is "most useful" for the iPhone 3GS, iPod Touch 3G, and both versions of the iPad. As with any modification to your iPad, be aware that any unofficial modification could void your warranty and is done so at the users own risk.