Wowbagger the Infinitely Prolonged was a character in the Hitchhiker's Guide to the Galaxy. He was accidentally made immortal and decided to occupy himself by insulting every creature in the universe.
In alphabetical order.
I loved this ridiulous idea (Douglas Adams is the man) and it was vaguely appropriate for me, given my fairly frank never-sugar-coat-stuff attidude.
This is actually the only website I've managed to get Wowbagger on its own as a username. People usually beat me to it and now I mostly use Wowbagger2004 (I got my GMail account then and used that...and it kinda stuck. I was sick of all different variations like WowbaggerTIP or Wowbagger1 etc.)