I was trying to think of a handle. A witty handle. And failing. So I decided I’d just go with what I felt like at the moment…
I think I mentioned in the past that in Hebrew, the name Nava is a woman’s name meaning “comely” or “beautiful.” It comes from the Biblical Song of Solomon 1:5: “I am black, but beautiful, O daughters of Jerusalem …” – the original word for “Beautiful” there is “na’va”
Just FYI 
Undersea (sub-) fiber optics (-light), which was the field I was working in when I first came up with the name to sign up with The Motley Fool. Of course, I quit the job barely one month later, but I’ve gotten attached to the name.
I am a consultant. People expect me to know everything. When I started my own company a few years ago, one of the guys that helped me get it launched asked what title I was going to put on my new business cards. I replied that I would put “All Seeing, All Knowing, Master of Time, Space, and Dimension”. He said it would not fit and suggested I just put ASAKMOTSD instead.
Really? I’m not a native French speaker (or even a very good French speaker, period), but your meaning is the one that immediately occurred to me when I first saw your username. And “Kingdom of Butter” in the location field only confirmed my initial reading.
I’m an adorable drunk. And only when drunk. Like now. (((Dope)))
I work for a radio station. Our program director (who happens to be my younger brother) receives new-release CDs all the time, many of them from vanity labels, and most of them utterly worthless. (Think Paris Hilton, although she didn’t release her crapola on a vanity label, it still wasn’t worth listening to.) One day a couple of years ago, we received a CD with the title “Sunrazor.” The music was so bad that at first we thought it was a joke. But when the PD called the publicist, she confirmed that it was really a new release CD.
This stuff was horrid. Imagine that a 13-year-old got an electric guitar this past Christmas, taught himself three chords, and talked two of his buddies into renting instruments to make an album! It was indescribably bad. Not just “not good,” but so bad that if this guy’s mother had heard it, she would have taken the guitar away and slapped him. OK, as part of our daily on-air schtick on the Morning Show one day, Andy (my brother the PD) played a few seconds of “Sunrazor.” For laughs, I pretended to like it. In the days that followed, I kept requesting “Sunrazor,” and the other on-air staff tagged me with that nickname.
Later, when the Sunrazor joke phased out (I was then dubbed "Prince of Dorkness) I was posting on SDMB under a variation of my real name and decided to use Sunrazor instead, and Sunrazor I remain to this day.
… blush smiley? Where’s my blush smiley?
trots out one of her WoW gnomes and makes her /blush
Basically, I tried various names that came to mind; mostly fictional characters and cool sounding words. Der Trihs from the Schlock Mercenary webcomic happened to be the first that wasn’t taken. I have a different username on every board I’ve signed up to.
I first joined SDMB using my real name. After a few posts, I decided that I wanted to choose another name. I sent TubaDiva a list, some of which were taken. **Crotalus **is the name of the genus which includes most rattlesnakes. I’ve always been fascinated by rattlesnakes.
Here it is… → :o ← It’s even *alt-labeled *“embarrassment” (try mousing over the icon)
Yeah, it’s not very good. Hey, I didn’t design these smilies!
Way back when, in the dawn of the internet… I decided on ‘terracotta’ because of I have very red hair and was a semi-practicing earth mom (Birkenstock wearing, NPR listening, bread baking, recycler and artist) but eventually lost that account and had to come up with a new one. What to do, what to do…? I tried to think of nicknames I’d had as a kid but the only one I thought of was 'You little dickens!" which didn’t really have any sort of punch to it. Then, in the back of my head I heard the haunting theme song to a so-so movie called “Terrorvision” and the ‘Red-Earth-Imp’ was born.
Now of course, there are quite a few imitators around so I am developing a new persona - RadialFly. I have the logo roughed out and have begun using it when I can’t have the Terrorcotta name.
(The real pissoff came when I found a website that’s using the terracotta soldiers from the Chinese tomb! <insert the rolley eyes!>)
I like old firearms.
“Martini Enfield” manages to combine expensive, sophisticated alcoholic drinks with the name of the Royal Small Arms Factory, maker of some of the finest firearms in history.
It’s also the name of an actual firearm, so my username manages to be a rather nifty username, witty play on words, and name of an actual thing all in one. 
I’m sure we’ve had a discussion on this topic before, but anyway - when I decided to be a bit more “semi-anonymous” I didn’t use a lot of imagination when I picked my new name. It’s just the way some people seem to slur the word “Canadian”.
I chose mine to reflect my warm and loving nature…
Initially my username was a variation on my initials; that seemed a little drab so I decided to name myself after one of my favorite Kinks songs.
“Fach” is German for compartment or cubby-hole. In the opera world it refers to the Fach system of vocal categorization: this goes beyond the typical “bass, baritone, tenor, mezzo, soprano” and groups voices further based on weight, color, endurance and so on. So voices are “pigeonholed” into certain roles. “Verwirrt” means confused. Fachverwirrt harks back to when I was constantly flipping back and forth between baritone and tenor of various sorts. I’ve more or less settled into a nice comfortable baritone, but I’ve used the name online for a while now and I’ve grown attached to it.
I was reading Sharon Kay Penman’s novels about Henry and Eleanor when I signed up.
My real first name is androgynous, so I enjoy having an obviously feminine username.
It’s what my niece calls me. Duh!
I am an administrative assistant for a whole gaggle of Engineers, whom I get along with very well. We are always joking around. When they ask me to do something stupid, which they invariably do, they say, " Real name, can you do this relatively stupid thing for me" and I say, “That’s Missy to you.”
A previous thread, FWIW: Explain your user name - In My Humble Opinion - Straight Dope Message Board