Oh, mine's boring. First name, last initial, just because I couldn't think of anything really clever whenever I signed up. I suppose I could have used Feathers, which is my maiden name, or Kimba, which was a college nickname. I have a couple of friends who call me Moon Pie (cause I like Moon Pies but don't eat many since I went low-carb), and I often follow that with "Frank Zappa's Southern daughter." Really, though, I just prefer my own name.
One day on the Civil War reenactors list we were making up Greek & Roman sounding names for ourselves, and I figured upon Kimberelius Fiddleopoulos Caudellus, Mistress of Vexology. It really does match my initials (the KFC part, anyway).
Some of you may have noticed that I call my husband Mister. Fellow Prine-ites will know where that came from. His uncle calls him Zan, as in Gitarzan. (heehee)