Scientists at the Keio University in Japan used a commercially available EEG headband to allow a human to control a character walking around the Second Life virtual world, all through raw brain power. Obviously this technology has tremendous potential for disabled individuals, and may also become a new type of joystick for controlling machinery and video games of the future.
Video demonstrating the capabilities in Second Life:
Press release: Keio University succeeds in the World’s First Demonstration Experiment with the Help of a Disabled Person To Use Brainwave to Chat and Stroll Through the Virtual World…
More info from Keio University in Japanese…