Ashton Kutcher & Demi Moore

Among the patrons on hand at Socialista for Ashton's birthday: Madonna, Gwyneth Paltrow, Salma Hayek and Bruce Willis. They are urged to get a hepatitis shot. The Kutcher bash was held on February 7. The bartender also served up drinks on Feb. 8 and 11.

Hepatitis A is spread by putting something in one's mouth that has been contaminated with traces of fecal matter from an infected person. Symptoms include jaundice, fatigue, abdominal pain, nausea, and diarrhea. Any patron who hung at Socialista is considered to be at risk, and the Health Dept. says they should get a gamma globulin shot -- pronto!

Bar owners estimate roughly 700 to 800 people may have partied there on those three nights.

UPDATE: Socialista has issued the following statement to TMZ: "Although no additional cases of illness have been identified, the New York City Department of Health is urging customers to get the vaccination as a precautionary measure. We are grateful for their efforts and we will continue to support them in every way possible."

Story developing ...

So let's see here: Ashton's party had Madonna, Gwyneth Paltrow, Salma Hayek, Kate Hudson, Eric Dane, Liv Tyler, Ivanka Trump, blah, blah, blah and ... not Wilmer.

Hopefully, Demi Moore can tell these playas apart!

We're just sayin'!

We were momentarily duped ... until he opened his mouth and started yapping.

On her way out of the Midtown celebriteria, Moore was greeted by an unholy crush of lensmen, and gingerly managed to get into her car. Dennis Franz, who hasn't done anything in years, also got plenty of attention. But the true star on display was a fresh white truffle -- worth, we're told, $11,000 -- waiting in all its rock-like glory to be cosseted, shaved and admired.

Much like Demi herself.

Centuries hence, cultural anthropologists will note that there was one human who never saw "That '70's Show," "Punk'd," "My Boss' Daughter," "Cheaper by the Dozen," "Just Married," or "Dude, Where's My Car," and didn't read a single tabloid or women's magazine, or lust after Calvin Klein underwear models.

Remarkable!

TMZ was there as Posh & Becks showed up arm-in-arm with TomKat and Will and Jada Smith at the Museum of Contemporary Arts on Sunday night -- with all the ladies sporting their very own interpretation of the Posh-bob. Cruise even flew in from Germany, where he's currently filming that Hitler movie, just to attend the party.

Other celebs who celebrated the British invasion included just wed Eva Longoria, super-couple Demi Moore and Ashton Kutcher, Brooke Shields, Jim Carrey and Jenny McCarthy, producing partners Brian Glazer and Ron Howard, and perhaps most random of all, Wesley Snipes.

While not quite a striptease in sweatpants and no bra, the guys from Boyz II Men aren't complaining.

Ashton Kutcher brought all the essentials with him, gun included, for an all-guy camping trip this weekend in the wilds of ... Malibu. With no girls allowed, Ashton and the boys got in some quality time with each other over a hearty bowl of ... cereal.

Now you know for sure, Ashton's packing.

The slim-bodied cougar bride of Kutcher went out with hubby and Penelope Cruz in New York last night, wearing a not-so-form-fitting blue dress and tent-like black jacket.

Does Demi have a little Ashton on board, or is it just a bad dress?

On their way out of the awards show, Demi and Ashton waved and smiled at shouting fans. One envious fan screamed the obvious, saying, "You're so lucky to have him!" Demi playfully mouthed back, "I know!"

She might want to ask for her money back.

Well, according to the resident analysts at CollegeHumor.com, not very much. The ribald comedy site employed a rigorously absurdist methodology to produce its very first ranking of the colleges where students can, in its own parlance, have "the most fun while putting forth the least effort."

No doubt the famous alumni and attendees of Michigan State University -- like James Caan, and Angelina Jolie and Christina Aguilera, who took correspondence classes there -- will be thrilled to hear that they've landed right at the top, with the most compelling mix of low SAT scores, late bar-closing times, and Greek-system density (among many other factors) amongst the fifty schools surveyed.

Big Ten schools did marvelously on the whole, with nine of its member colleges placing in the top 20 of the CollegeHumor rankings, meaning that such notable alums as Madonna (U. of Michigan), Kevin Kline (Indiana U.), and Ashton Kutcher (Iowa) were privy to some of the finest college-life available to young Americans, even if it was a few years ago. Will Ferrell's beloved University of Southern California apparently isn't a total hotbed of salacity, as it came in 34th.

Not known for her vocal abilities, listening to her sing this track might surprise you. And yes, TMZ has confirmed, it's really Demi singing. Cool!

While training to play a US Coast Guard in his new film, Ashton Kutcher had one man's body in mind for inspiration -- Brad Pitt.

"I went and saw Troy, I was with my wife and with a friend, and every time Brad came on and he was like naked or whatever, they were like 'Ohh', and I'm like, 'I'm right here, I'm sitting right next to you,'" says Kutcher, "I knew this movie was coming up so I went out and hired Brad Pitt's trainer."

The self-admitted "pack-a-day smoker" who "hadn't really worked out since high school" (damn him for naturally looking so good) had a tough time getting into top shape and admits he's already on a downward spiral since shooting wrapped.

"No. I'm done... I'll train for the next one, it's fine, I'll run a little bit, I'll stay in shape, I can still do some pull-up's and I do some push-up's and stuff but it's just brutal. It's a full time job it keep yourself in that kind of shape, it's no joke."

"The Guardian" and "Open Season," also starring Kutcher, both open this weekend.