I won't bother nominating myself because I think Shaw has me beat, but I'm also pretty nerdy. I was in one of the nerdy social groups in a high school that catered to nerds (a Science and Technology magnet school). I learned how to program my graphing calculator and at one point I could operate it with my eyes closed (not just do operations/math, but program it). I bought a second graphing calculator primarily for calculator games. I broke through my Middle School's network security system. I've learned a few programming languages, but it's not my thing--same with languages. I've pretty much forgotten the specifics of any given programming language, but I can usually figure out what's going on in languages that I have no experience in. I've also done some CAD work in Rhino (not just f'ing around with a pirated copy of 3DStudio Max). I read books like
Wealth of Nations for fun and went to the University of Chicago specifically because of its association with Milton Friedman. I've done the whole (A)D&D thing, including reading a lot of the Forgotten Realms novels. I drive stick out of principle. I played Counter-Strike competitively and was an active member of the "gaming community" a few years ago. I'm still a computer gamer at heart and generally scoff at consoles. I build my own desktop computers. I was a co-founder of my high school's "Computer Repair Club" (ie, piece together scrap hardware and figure out how to make it play games) and Sailing Club. I listen to some pretty obscure music and have been in a professional-level chorus. I was offered money for writing for a technology blog, but preferred to do it for free. My articles have been on the front page of Slashdot, Digg, Fark, etc. I have, at times, owned 3 (or more?) pairs of the exact same pants.
I've gotta say, though, I've been putting a lot of my nerdy activities behind me. I haven't played pen and paper D&D in a long time and I really don't game anymore either. I still read and keep up with technology, but it's hard to keep up nerdy habits when you've got a job. I like to think I've still got it in me, though