Mike Begum, who goes by pseudonym Broly Legs, has a condition called arthogryposis. In effect, he has very limited use of his hands and his feet, only being able to really use one finger and a thumb on his left hand. So, how on Earth is he able to play Street Fighter IV and play it competitively? With. His. Face.
You really have to watch this video to believe it. He moves the control stick around with his cheek and he hits the four face buttons by pushing his tongue around into his other cheek. He uses Chun-Li as his main character and he's a consistently good performer at real competitions. He plays mostly in Texas and he also happens to be a formidable foe in the Smash Bros. series too. Crazy stuff.