Of course they wouldn’t tell if they were, but with the thousands of members there must be a few.
Does anyone have a few guesses for which members might be? Or is it all obscure?
I’m not famous, not even locally well known, so don’t guess me.
aha is a (former) rock star, Eve is a published writer, The Bad Astronomer has some popularity in certain circles too.
And my picture is in every post office in Holland!
I don’t have any guesses to offer, and personally, I don’t really care. Even if I did know of a particular Doper here who was a celebrity in disguise, I wouldn’t go around broadcasting that fact, for I feel that would be infringing upon that Doper’s wish to remain anonymous.
It’s my impression that a lot of celebrities feel the weight of public exposure, and crave having some part of their lives be private and reserved for themselves.
If I were a celebrity (and I’m not, so don’t bother guessing), I wouldn’t mind having the means to interact with other people without the nuisance of constantly being asked for autographs, what’s my next movie, what was Bruce Willis really like, etc.
I say all this, Zamboni, to explain why you’re not likely to get any firm answers regarding your OP. 
I’ve been on here since 1997. Here is how fame breaks down as my understanding.
-
Opal is sorta famous. She is all over the net, designing web pages and stuff. I have heard her mentioned by people who know nothing about this place.
-
Michael Moore once posted through a friend. It was a close to a movie star/director posting as we have gotten(we believe).
-
Eve writes.
OK, I will go ahead and admit it: Dick Sargent, of Bewitched fame–he was the second Darren, after Dick York–was my great-uncle (father’s uncle).
Curse it! My secret is out! The paparazzi will no doubt be pounding at the door shortly, snapping photos wildly to feed the public’s bottomless hunger for photos of Dick Sargent’s grandnephew!
Autograph requests will be taken only on a cash-and-carry basis, please.
In reality I am a famous basketball player. Oh, wait, I’m 5’5" tall and weigh about 260. Now, if somebody slipped me some Douglas fir DNA, with my girth I might be about fifty feet tall. Does this help?
What’s the reward up to? 
I had plans to be a ping-pong star, but I did not understand the game.
I sat up all night before the big match marking the backs of cards with a felt-tip pen.
I get fan mail. Does that count?
Not if you solicit it.
Believe me, I’m not getting fan mail from this place. 
My apologies.
The hell?
Isn’t anyone totally amazed and impressed by the fact that Dick Sargent was my great-uncle? Jeez, that’s been my best conversation-started for my entire life, and suddenly it’s stopped working? Oh great, now I’m going to have to come up with another one…
OK Jackelope, just to soothe your battered ego, I’m so impressed that your great-uncle was Dick Sargeant…but I can’t afford to get your autograph just yet…will you forgive me?
And you Jinwicked, you wanton hussy, just WHERE do you get fan-mail from anyway?
[big-headed rambling]
Other people telling other people about me, I guess. People who buy stuff from me telling their friends. Other message boards I don’t post on, where I’m more mystified since I don’t have an actual presence there.
I’ve been linked from Cruel.com twice, Memepool.com, bunch of those kinds of places. My Diversions pages get around quite a bit, too.
I’ve gotten only two or three msgs from SDMB members, and they weren’t really what I consider “fan mail.” (Though I have sold something to at least one SDMB person that I know of.)
I can tell 'ya that this month, I’ve had about 250 hits come from my sig on this site – and no telling how many of those were repeat visitors. I tend to not notice referrals until they get close to the thousands.
[/big-headed rambling]
I’m…The Searcher!
(I loved Danger Theater…I miss it)
I was Dirk Diggler’s body double.
Dick who?
Bewhated?
This thread topic pops up sometimes, and I am irresistably drawn to it. I’m always curious to see if some new celebrity has turned up here. How weird to see my handle in the first response!
Some folks here are famous in different ways, and don’t make a big deal of it. They don’t downplay it either. I’ve done some media stuff (ironically, the biggest was probably Art Bell’s show in June 2002), and wrote a book. Others here are far more well-known. Cecil, for example. Eve has written lots of books.
By the way, I like the phrase “certain circles”, Coldfire.
Anamorphic is a movie director and writer. I doubt if I’m blowing his cover since he even had a thread detailing the making of his last picture.
He did a short comedy a few years ago that won a metric shitload of awards, and his first full-length feature starring People You Would Know is in the can and hopefully will be distributed soon. He’s also in the middle of writing his next feature.