The Luke Arm

The Luke Arm is an advanced prosthetic device that is, um, head and shoulders above the rest. You can watch videos about it at medgadget. I only watched part 2, but it provided a nifty and simplified version of how it works. People, listen: This thing can pick up grapes! There was another guy, who had no arms but two Luke arms, and was able to disassemble and reassemble a gun, and then fire it. All of this with minimal training too!

It may be a long video (almost 15 minutes) but there are some really neat things going on.