At Mobile World Congress 2010, NTT DoCoMo demoed a new headset that allows you to control your phone with eye movements. The eye-controlled user interface lets you move your eyes in various directions and the phone will then read them as different system commands. The headset sense movement by looking for tiny changes in electric charge; apparently, our corneas carry a positive charge. Who knew?
It was all pretty interesting stuff but frankly, I just felt bad for this guy who had to stand there moving his eyes up, down, left, and right for huge chunks of time.