Stephen Torrence is a self-described geek who posts ASL (American Sign Language) videos for popular (and not so popular) songs on YouTube under the user name CaptainValor. Torrence is hearing and was introduced to ASL through a high school friend who enjoyed signing with her mother. He graduated from Texas Tech and minored in ASL. He got his start making videos for his sign classes and they were so well-received, he decided to post them on the internet. PopEater posted one of his videos and he ended up with over 18,000 subscribers. Torrence proves his geek cred by being a big Jonathan Coulton and Portal fan.
Here are my favorites of his videos:
Jonathan Coulton's "Re: Your Brains"
"Still Alive" (also written by Jonathan Coulton) from Portal
And here's an interview with Torrence by How Stuff Works