It's amazing what really smart people can accomplish when they put their minds to it. Appearing at the All Things D conference, inventor Dean Kaman shows off the replacement arm he is developing primarily for troops who have been wounded in the war on terrorism.

There's a touching moment about half-way through where Kamen shows video of a guy who lost both his arms using this impressive robot-prosthetic replacement to feed himself. The man's wife was apparently in tears as she watched her husband feed himself for the first time in 13 years.