I know this is a generic thread for most forums but there a couple of usernames that I've been curious about the origins of. I'm gonna take a punt at a few to get the ball rolling....
snowflake - Delicate white man
spud - got a head only a mother could love
ndf - No Damn Form
Captin Commuter - You have a fetish with getting places regardless of where they may be
Nexus - you're really just emo and you are trying to be deep by saying you have internal ways of shifting your gearing/angst.
Mine, if you hadn't already guessed, is my first name and the first 2 letters of my last name, not some poor attempt to trick you into thinking I'm the lead vocalist in a Hip-Hop crew.