Great idea for a thread! My name is Dave Gardner, but when coming up with a handle for web forums, tried to come up with something that defines me. so the "geek" comes from my IT computer work (along with my general geeky/dorky/nerdish nature) and the "runner" comes from my 25+ years of running. "geekrunner" just rolls off the tongue! My avatar of a roadrunner with running shoes represents my membership to my old hometown's running club, the Club Kokomo (IN) Roadrunners, where I cut my teeth in competitive road running and racing. I use "geekrunner" for most of my other forum memberships, except for the occasional site that uses my email address, and our local mountain bike club's site, where I just screwed up and used my real name inadvertently.
As always, your geek