Japanese researchers have developed head gear that lets people control devices such as an iPod using their teeth. Now that is not really new, except when you take in mind that they are not actually biting the device. Their technique uses infrared sensors and a microcomputer to let people operate music players by clenching their teeth. The computer is able to see the difference between browsing and other teeth activities such as chewing gum, talking or calling. The research team at state-run Osaka University hopes to put the device to commercial use for music players and believes it can eventually be adapted to run cellphones, wheelchairs and other products. Not sure why it's useful, but it's cool, and it takes us and step closer to a perfect man-machine symbiosis.