Since we're all sharing.
Mine is a modification of an older screen name, which in and of itself is a bit of a joke. More 'heh' than "haha'. It involves French and words that sort of sound like other words, but it isn't clever in the least, I promise.
I've been using another name for almost a decade, though it gets very little active use now. If you happen to see a Kell4077 floating around in the internet anytime since the early 00s, and they've pissed you off, my bad. Unless you were being a real douchemuffin. Anyway, it's just a mixture of Kell from the Star Wars X-Wing series (Wraith Squadron > you), and the unit designation from M*A*S*H. What can I say, I was in junior high or early high school, mashing together two things that I liked seemed a good way to do it.
Let me think...I spent a lot of my Warcraft years as Teng Darkheart, a sufficiently angsty orc warlock name for sufficiently angsty (and grumpy) 'omg so dark' roleplaying.
That's most of them though. Some people have, like, a billion names, I could never keep up with that.