I think it goes back to being a little kid and my grandmother giving me one of those books that has your own name in it (Doug in this case). The build is done now but I'll finish the story anyway. Those books use your name spelled backwards (Guod in this case) to be the name of your friend in the book. I guess I liked that idea enough to extend it to my full name (Douglas and Salguod respectively in this case).
When I first signed on to local bulletin boards after buying a 1200 baud modem I needed a name and that was he only one that came to mind. When I went to get a b account to backup my class files that seemed the best name since it had been doing well so far. The clue is in my real name field (A bit backwards). (These parenthetical facts are getting tiresome, but parenthetical is a cool word.)
Occasionally have gone by prudeboy on icb. What else are you supposed to do when everyone else is talking about icking and stuff and you don't know what to do with that?