I've been TorontoTrekker
since I first joined. It's pretty descriptive of me, although the convention I volunteer for, which used to be called Toronto Trek, changed its
name to Polaris in 2007.
If I were to change my name, the only other name I use online is a nickname that was given to me by a bartender at the place I used to hang out at, when I was telling him about how I was working on three conventions and trying to get a fourth one started. He said, "Your problem is, you're the boy who can't say 'no'." That's how I acquired the Livejournal handle "boywhocantsayno", and I use it in a few other places as well. I enjoy letting people misinterpret its meaning.
(Though I probably shouldn't use it on dating websites...