Check out the late John Entwistle's performance on the bass, begins at 4:17 in the video. I don't think my fingers are even capable of moving that fast:
http://www.youtube.com/watch?v=xTEmldzx1xE
(To keep this post on-topic with ham radio, WB6ACU jumps in at 6:18 in the video.)
P.S.: I also played the double string bass in the school orchestra. I had one loaner instrument at school and another loaner at home, courtesy of the public school system. It saved having to drag the beast around. All the other kids playing the violin, viola and cello had to buy their own instruments.