At one point I was going to changed mine to "d-cubed" or "3D" -- but everybody wanted me to keep "physics girl phd" (to explain, I was writing my thesis when I discovered PF online, and found being a homework helper a great procrastination device). D-cubed roughly matches my "initials."
I like "basil" (probably because, like turbo, I like the spice-- but as a teen I also liked a book with a character named Basil), but then i'll confess to liking "lisab" as much or more. I guess we get to know each other by certain names and therefore poo-poo it if someone wants to switch. I guess if someone switches then they definitely should keep around the same avatar for a while to ease the transition.