Quote:

He gradually lost the use of his arms, legs, and voice, and is now almost completely paralyzed. The computer system attached to his wheelchair is operated by Hawking via an infra-red 'blink switch' clipped onto his glasses. By scrunching his right cheek up, he is able to talk, compose speeches, research papers, browse the World Wide Web, and write e-mails. The system also uses radio transmission to provide control over doors in his home and office.

http://en.wikipedia.org/wiki/Stephen_Hawking#Illness

Same birthday as mine, he has.