Dean Kamen's robotic "Luke" arm.

You know of Kamen. He's the guy who invented the Segway and who invented some of the stents that keep Dick Cheney's black heart alive. (After living in Wyoming in the 80s when Cheney was a Congressman, I never knew Cheney had a heart, or I'd have imagined stakes instead). Here's the latest, probably for the uber-rich.