Guy, not one but two. pod2g has done very great work and finally find solution to jailbreak iPhone 4S and iPad 2. Previously we have reported that pod2g will soon announced to the way to untethered jailbreak iOS 5.0 and iOS 5.0.1. Now taking an advance step to the next level, they found a way to deal with A5 processor which has been the main obstacle for jailbreaking work.
However even with the claim, we are still far from the perfect tool to jailbreak iPhone 4S and iPad 2. However thanks to his great work, he kept updating and finding solution to the obstacles. However with the latest update on his blog, the A5 processor cache is not a problem anymore.
You can follow this update on his blog for more information.