[David Hyman] built this device to control a LEGO claw. One one end of things is the part you wear, that measures movement of two fingers and your thumb. On the other end of things is a LEGO claw with three opposing digits. You move, it moves. The claw uses light sensors and a gradient strip for position feedback. There is also an up-down wrist action that uses a touch sensor as the input. This is impressive enough to give the sniper rifle a run for its money.

http://hackaday.com/2010/06/12/lego-hand-controller/