Well, I have a long history of miscellaneous nicknames...
I've been camping on internet since 1993, so I've used nicknames, and dumped them because people usually don't research if something is used, and even worse, just steal cool names right off without even telling... (Not that I've ever expected anything else. )
I used Guran when I started out. I had my own phantombot tossing out Phantomquotes at (not so) apropriate times. It wasn't too original though, so eventually I had to change to something different. I called my self the Technolink for a while, until I ended up in a minor depression, and decided to go with the more "fitting" Guttergod, i figure this was mid 1994 or something, which has stuck with me, and there are a few sites out there where I can still be located by that nick. I've seen some use of Guttergod that is not me though, so apparently more people than me has thought it is cool (it's original enough for me to be fairly sure that their use of the nick could be traced back to something involving me in some way ).
For a brief time I called my self dr.znygg (roughly translates to doctor handzome), guess I was rebelling against my own nickname.
Currently I use "mickeko", "micke.ko" or "mike-cow" pretty much everywhere. All based on my real name "Micke".
(Oh, and for those of you who tend to call me "Mick", It's perfectly fine, or I'd hace corrected you a long time ago. )