The Dream Team of iOS code junkies have released their Absinthe A5 untethered jailbreak on both Windows and OS X for iPad 2 and iPhone 4S owners. The new jailbreak will release your iDevice from Apple's grip and allow you to tinker with it in new and Apple-unauthorised ways. Notably, this newest method is untethered, meaning the jailbreak will be retained after reboots.
If you fancy some jailbreaking action then head on over to greenpois0n where the standard warnings and trepidations associated with the jailbreaking process, as always, still apply.