Back in the days of BBSs, I had a different handle for every system I was on, sometimes random, sometimes thematically apropriate. I got into the habit of signing things "-S". Karmakaze dates back to that time. I thought it was neat. It has a little icon, too - a sort of yin-yang symbol with a baloon tail trailing from it.
Over the years, the amusement value of nicks dimmed and I usually just used "sarudy", which is just my first initial, my middle inital, and my last name. It's not very exiting, but it works. It also lets me still use "-S", since I still avoid using my first name online. Things have calmed down a bit from the days when males vastly outnumbered females online, but I was hassled enough by net.romeos over the years to enjoy being neutral.
Then, horror of horrors, sometimes I found "sarudy" would be already reserved. Often, I susupected, I had probably reserved it myself once, then forgotten. So, I did a quick little phonemic shift from "Sylvia" [my real first name - I'm not that paranoid, and I figure I can trust you guys not to stalk me :) ] to "Zulfiya", and lo! I had a name that is rarely reserved. I did find, though, that "Zulfiya" is an actual name, in Azerbaijan (one of the former Soviet Republics). Every now and then I get messages from lonely Azerbaijanians, thinking I might be a countrywoman. But I'm not.
More recently, I decided I wanted to have a gender neutral nick again, and one that was not immedialely able to be linked to me. I remembered "Karmakaze" from my BBS days, and ressurected it. I quite deliberately did not use it on Slashdot, because I thought it might come off the wrong way.
So, now I have three id's, that I use depending on mood, whim, and how easily I want to be identified...