The mouse and keyboard were invented before the Internet even existed. Since then, countless technological advancements have allowed for much more efficient human computer interaction. Why then do we continue to use outdated technology? Introducing Gmail Motion — now you can control Gmail with your body.
How it works
Gmail Motion uses your computer’s built-in webcam and Google’s patented spatial tracking technology to detect your movements and translate them into meaningful characters and commands. Movements are designed to be simple and intuitive for people of all skill levels.
Continues @ http://mail.google.com/mail/help/motion.html