I thought I had responded to this thread, but my story is so boring, I guess I didn't.
I originally was using my real name on TE, until 2-3 years ago, someone I used to work with 20+ years ago found me by searching my name and it came up on a TE thread. This isn't really awful, in light of Facebook, etc., but I decided to change to a screen name. I really couldn't think of anything original I liked that hadn't been taken. My IM screen name is Crankin + my first name (which I chose because I couldn't think of anything and Crankin + DH's first name is his IM screen name), so I dropped the first name part from Crankin. I guess it would i.d. me as a cyclist, even though I am not particularly "crankin," in terms of speed.