This armless guy plays guitar with his feet as he sings. I haven't found out where it was filmed. Hit Play button or follow the link below to watch the video.
Link
Update 1/12/08 by Alex: It's Mark Goffeney, filmed in Balboa Park, San Diego - Thanks Hari and Eric!
http://maps.google.com/maps?hl=en&ie=UTF8&ll=32.731584,-117.149279&spn=0.001575,0.00339&t=h&z=19
I've seen him there a number of times, right by the crazy opera lady with a tambourine. When's somebody going to put HER on YouTube?
On a related matter, now I know it's possible to play with the feet, and knowing that some dude played 2 guitars at once, it should be technically possible to play 3 guitars at once.
Wow. I'll sleep better tonight.