Tongue control for movement ! (Concept)

When I first watched a video about Oculus Rift on youtube, one thing did not feel right, that is using a xbox controller for foot movement, seemed kinda weird to me !

So how about using tongue movement inside mouth of user for controlling movement in the Virtual World !
Well, the hardware is pretty simple, using an "Ultrasonic Doppler Transceiver" module in Oculus Rift to pick up gamer's tongue movement and transform it into virtual motion !