Neuroscientist Paul Bach-y-Rita's work on sensory substitution has spawned BrainPort, a sensory remapping unit that uses the tongue as sensory input interface. BrainPort uses the tongue to map the image picked up by a camera into discrete electrical points with up to 600 image points. BrainPort has also been used to correct balance in patients with vestibular dysfunction. See the facinating video on Wired Science:
A rather nifty table of applicable studies on posturography to be checked out before bulding your own.
A very useful thing to have and I will post my version eventually I promise.
Epley image courtesy http://www.australianprescriber.com/