The Chair Driven by the Tongue
From: Popular Science - 12/2007 - page 90

The traditional "sip and puff" approach to quadriplegic wheelchair control -
sucking or blowing into a straw to steer the chair - is neither convenient
nor terribly hygienic. The Think-A-Move E-macc instead uses an earpiece about
the size of a hearing aid that picks up pressure changes in the ear's
auditory tube, which occur when the user makes small, subtle tongue
movements. Those movements can be mapped to particular commands like "speed
up" or "turn right". In trials, the Think-A-Move, designed in conjunction
with engineers at Southern Illinois University, identified commands correctly
97 percent of the time, and users could talk, eat, and cough without
compromising its accuracy. $5,600. 

Read this article at:
http://www.popsci.com/popsci/flat/bown/2007/health/item_91.html

Link:
Think-A-Move
http://www.think-a-move.com/