Maxwell Smart had his shoe phone. Captain Kirk had his communicator. One day soon, we may be able to chat hands-free and hassle-free on a tooth phone. Two British design students have developed a prototype of a phone that would be fitted directly into a back tooth by a dentist. This filling in your molar then would transmit sound through your jaw bone into your inner ear.The technologies required to make this phone actually work, however, do not yet exist. London Royal College of Art student Jimmy Loizeau and graduate James Auger theorize that if a wireless receiver and microvibration device were implanted into a tooth, audio signals could be sent to your inner ear through bone resonance. Alas, a still-to-be-developed technology would be required to convert those vibrations to audio signals.But just think of it: The tooth phone could be discrete. The volume would be just loud enough to be audible, but only you would hear it and respond (though others might wonder why you were talking to yourself). The inventors suggest that the receiver could also be configured to pick up radio signals, making your new MP3 player pass\u017d. This unique prototype is on display until November at the Science Museum in London as part of the "Future Product" awards show.Talk about giving new meaning to "that sound ringing in my ears."