I heard from a punk-rocker I know in england that over there, the term "banjoing" refers to hitting somebody hard enough with a heavy object to do serious damage. I guess in some cultures, the banjo is considered a weapon (which may indeed be a step above considering it a musical instrument).

Playing with bluegrass musicians a lot, I hear a lot of banjo player jokes. (They're usually told in front of the banjo player, with a reasonable expectation the banjo player will not understand them.) My favorite, until recently, was:

Q. What's the difference between a banjo player and a municipal bond?
A. The bond will evenutally mature and make money.

Joe