It looks like a regular U-lock but contains high-pressure skunk gas. Anyone trying to cut through the lock will release the foul smelling gas all over themselves and it will make them vomit and ruin their clothes. I love the idea.
The lock costs $100 and obviously has to be replaced once the gas has been released but I think it's exactly what I want on my touring bike.
The project is being crowdfunded by www.indiegogo.com/ and they have already reached their target of $20,000.
Their website is http://skunklock.com/