What does your lj-name mean? Where did it come from? If you are reading this, please answer. Don't let us all down.
In the spirit of participation, I'm happy to begin: archmage was the easiest and shortest version I could get of the main online handle I was using when I started my LJ, which was "Archmage Chaos Blackflame" (there were others, depending on the site or circumstance, but this was the primary one). The wizardly moniker came from the fact that I had been interested in Tarot cards for years and years, and identified with The Magician (he who uses the forces of the world for the betterment of all)...and being a life-long D&D player probably didn't hurt. "Chaos" came out of the fact that the only force I find myself able to believe in is that of Primal Chaos. "Blackflame" came from the "the black fire", the rabbinic way of teaching the Torah in the written tradition, and as I was writing a lot at the time, I liked the way that fit me...though, admittedly, mostly I just thought it sounded cool. ;)
In the end, I came out with an LJ-name that was short and distinctive, plus easy to remember and tell others without having to give them strange spellings or symbols or underscores, etc.
So, tell us about yours.