GreenPoison has just release Absinthe 2.0 which will jailbreak (untethered) your iDevice if it runs iOS 5.1.1. This jailbreak tool works with all devices (The New iPad and iPhone 4s included) running iOS 5.1.1. so if you’re on a lower version, make sure you update. However, be ware if you have a locked device and want to preserve your unlock, you’ll need a custom IPSW which can be created with RedSnow. Look for the internet for a lot of tutorials on how can this be achieved.
Once your iDevice is updated to 5.1.1. head over to the Absinthe site and download Absinthe (Windows/Mac/Linux). Then, plug in your iDevice, launch Absinthe, click “Jailbreak,” and wait for Absinthe to complete the jailbreak.
Check out the GreenPoison page below for download links and more info for each device.
Disclaimer: Jailbreak your iDevice at your own risk! I will not be held responsible should anything go wrong during the process and you brick/damage your device.