This is fascinating. Using the tongue as the interface with the brain for Brain Computer Interface (BCI). Cool idea.
Lotsa nerve endings, very sensitive, can discern pixels up to 64k...with some training this could be very interesting. And if they can work with the taste buds you could flavor colors...
a growing body of research indicates that the tongue may in fact be the second-best place on the body for receiving visual information from the world and transmitting it to the brain.
[linky]