EyePong: Play Pong With Your Freaking Eyes (built at Barcamp Vancouver) (techvibes.com)

Should also add a link to one of the developers blog posts on the project: http://jonchui.wordpress.com/2010/11/21/492/

Thanks for the link @nick! I should also mention that I wasn't the only dev on the project at all. @appskicker built the backend & started it.