Mebbe in a homage to A. A. Milne…
NowWeAreSix
(hehe)
Spam in Five Weeks
Splunge
Breastless Wonder
Colonel Klink
BOING
TODAYisTHEday
Crapsicle
FUTONcity
MyDogAteTheComputer
Dr_Paprika, you forgot Five of Nine. 
Doh!
Another great fictional character name (and one that I had considered for myself): Anthony Fremont (TZ fans should recognize it)
You guys are the best! I think my next username will:
not embody any reference to “Five” or to any other number.
not end in “-inator.”
not be any of ssskuggiii’s suggestions (“Breastless Wonder?” “Crapsicle?” Where the hell did those come from?).
Mullinator, life is change. Change is life.
TheThill, I don’t know if it’s easy to change your name, but I know several around here have done it.
Dr_Paprika, you obviously thought long and hard to come up with all those ideas. I really appreciate it.
I am ineffably disappointed that Eve hasn’t been by here. There is no doubt, anything she suggested would be positively sopping with class and wit.
I’ve always liked Snookums.
Excuse me, Five, but could you let me know whether my reference to “Precious Joe” was correct or not?
Just need to know if I’m using the right search engine.
Good luck with the name change!
Ice Wolf:
“Possible Joe.” Yes, you’re right, that’s from the juvenile novel Danny Dunn and the Time Machine, and I’m very pleased I wasn’t the only one here who read it.
Danny and his friends accidentally took a time machine (which was not a phone booth or a sports car, but an entire laboratory, take that, Dr. Who and Doc Brown) forward in time four days, where they picked up an additional copy of their friend Joe (who was already in the lab with them, hence the modifier “Possible” for the future version of himself).
Then they took the lab back 200 years, where the time machine broke down and they had an adventure with Benjamin Franklin. Joe and Possible Joe were equal partners in the story, almost like a pair of twins.
Crazy Contraption
WomenAndChildrenFirst (or as a variation, WomenAndChildrenLast)
eviF
ParFive
EveningDew
Five, we seem to be hit with mid-winter blahs simultaneously: Should I change my name?.
How 'bout you change your name to jti, and I’ll change to Five, and we’ll play with people’s minds?
Hey, I wasn’t awake yet at school and I was bored out of my mind. Remember, this was the day when I taped my breasts down with duct tape. Hmmmm,…
GreenTeaMonster
Barbasol
nilpahCeilrahC
ginsengANDhoney
Send an email (from your registered SD address) to Tubadiva or me, and we’ll change it for you. We can either deactivate your old name, and you can start with a fresh name, or we can change the name on your current registration, so that you can keep your post count. Just tell us which you prefer.
Note: We won’t do this every week for you, so don’t get any bright ideas about changing your name every week.
Also note: So far, we are not recycling screen names. Using Slythe, for instance, is out.
Lynn
Administrator
For the Straight Dope
Sapient pearwood
Tough Like a Cowboy–because I keep hearing it in a commercial and I’m hoping giving this phrase away will keep it from taking residence in the part of my brain already responsible for crappy song lyrics.
Seeing as how it’s 3 o’clock in the morning, perhaps some random free association will give me some ideas to suggest. Warning: The following suggestion list has not been subjected to any sort of sanity filter and some of them are based on injokes from other places:
Monkey Stomp
Fun Size
Today’s Mail (or Today’s Male)
Death’s Head Mask
Faxed Chicken
Warper of Reality
Stepford-Wolverine
Squeaky Penguin
The Word Psychotic
That’s enough for now…I have to go to bed.
Damn you Rosebud! I wanted to say that!!! 
I always wanted to be Eurotrash but you are from one of the other continents, right?
BornDodgy:
That’s right, I’m from one of those non-Europe continents.
Kat: I like the sound of “Tough Like a Cowboy,” but it’s too long…and I’m not (tough like a cowboy, that is).
“Squeaky Penguin” sounds pretty good.
bibliophage: Please elaborate on “sapient pearwood.”
jti: Absolutely not.
Lynn Bodoni: Thanks for the 411. I promise, I won’t be attempting this every week.
I’ve whittled down the current suggestions to the following:
Possible Joe
Wax Tadpole
Phidippides
(I know what I told you about these two, Mjollnir,
but the more I think about them the more I like the
sound of them)
Gotta say nothing else I’ve read here has really grabbed me. Of course, I’m still waiting for input from Eve, who apparently hasn’t even visited this thread. [sub](sniff sniff)[/sub]
If you are a Simpson’s fan how about Rory Calhoun or Shiney McShine?
Given the unicycle link on your homepage, how about Unifive? But seeing as how you’ve disavowed any usage of “Five” I doubt it.
Or, given that you’re into acting, how about a reference one of the great blacksploitation movies, Sweet Sweetback?
Or from “Blackadder,” Baldrick?
Hell, I’ll just list them:
**Timmy O’Toole
The Big Chicken (the one up in Roswell)
PBR
Mr. Coke
**
If I think of any more, I’ll let you know.