My id comes from playing a musical instrument called the Chapman Stick and the name just sort of stuck (sorry for the pun).
You might have heard the instrument if you are a King Crimson or Peter Gabriel fan (its the bass line for Shock the Monkey). It is also the instrument Hawat played as the baliset in the original Dune movie.
Here is a picture of the Stick, but not a picture of me:
I wish the reason I got the name was because I was really lean, but regularly trying live fire recipes in the prof's books and smoke scented dining establishments has made that nearly impossible.