Using the tongue as interface seems to be a new innovation. Researchers at the Florida Institute for Human and Machine Cognition worked out an application called "Brain Port" that uses the tongue's ability to detect sonar echoes to control a PC.
"Everything nowadays is so ubiquitous with mobile computing, and we need to find new, hands-free ways of interacting for environments where your hands and eyes are busy," she noted. "I could see something like this being used in cars."
In the human adaptation of this natural strategy, researchers have users stick their tongues into a red plastic strip, filled with microelectrodes, to retrieve information from such instruments as electronic compasses or hand-held sonar devices (...) the project also aims to enable infrared vision via the tongue, resulting in the appropriate tongue-twister of "infrared-tongue vision."
With infrared-tongue vision, divers, soldiers, or pilots could see behind themselves or move in the dark without night-vision goggles, according to project lead scientist Anil Raj.
Why do I blog this? actually I find curious to use the tongue, especially because it raises new questions in terms of affordance, user experience, and involvement in an interaction (what about hygiene?). Let's have video games using this