A singular lack of imagination is probably the deciding factor in my decision to use my real name. Other reasons: A name is something you are given, I kinda think that giving yourself a name is tantamount to tempting fate (look at poor old Turin - the Homer Simpson of the Silmarillion); I would spend too long worrying about the appropriateness of whatever I called myself (now why on earth did I call myself Morgoth?); I am pretty happy with my name anyway (how about Smug the Dragon?).

There is also the snigger factor. Sometimes when I'm posting or lurking, someone will come along with some totally overblown screen name and I just sit here and snigger.

I find the use of avatars in chat rooms/ bulletin boards interesting. My theory is that, in general, people who use their real names tend to want to try to give the impression that they have a foot in the real world for whatever reason. Those who use avatars prefer to immerse themselves in their virtuality as much as they can.