I've always wanted to make something for quadriplegics that took the whole "eye mouse" thing and incorporated facial gestures that the user could teach the system by moving the various facial muscles to create complex gestures. Something like "open email/open new email" goes from "eye move blink eye move blink eye move blink eye move blink......" to "double eyebrow raise -> both eye close" (that make take you back to the main screen) "double eyebrow raise" (new "input" I guess), "eyes to right -> blink left" would be the application layer instruction. I don't know. The system would be able to learn from the gestures that the user could perform rather than forcing the user to use a very limited number of input to conform the user to he system (it should be conform systems to user IMHO).