My icons I choose based on my general geekiness.
I use this one most often cause well frankly it is a cool image. I like the notion of cycles and that a thing is not whole one thing or another. No begining no end. It should be pointed out that this image is also related to an old show i loved called Millenium. A solid horror television show.
Bogart. The classic of tough guy cool. Unlike cagney though all of Bogey's heroes had brains as well as guts.
Dr. Quest is my symbol for the classic intilectual and you will occasionally find me bringing him out when I am on the lecture or cerebral.