More about tongue-based interfaces. This is a bit old but I ran across it yesterday: using the tongue as a "surrogate eye" (News from 2001).

Researchers at the University of Wisconsin Madison are developing this tongue-stimulating system, which translates images detected by a camera into a pattern of electric pulses that trigger touch receptors. The scientists say that volunteers testing the prototype soon lose awareness of on-the-tongue sensations. They then perceive the stimulation as shapes and features in space. (...) The Wisconsin researchers say that the whole apparatus could shrink dramatically, becoming both hidden and easily portable. The camera would vanish into an eyeglass frame. From there, it would wirelessly transmit visual data to a dental retainer in the mouth that would house the signal-translating electronics. The retainer would also hold the electrode against the tongue.

(Picture K. Kamm/U. Wis.-Milwaukee)

Why do I blog this? though this is designed for blind people, there are some intriguing potentialities in terms of human-computer input!