Check out this video of Bill Clements, playing with one hand!
Clements lost his right arm in an industrial accident in 1989. He released his first CD, Undergroundalienbass in 2005.
His bass is also unique, using a “fret-groove” system where the frets are actually concave and carved out of the neck rather than laying on top.
You can check out more music and videos on his MySpace page.