It used to be that what you were wearing on the red carpet was what made headlines the next day. Now, it’s what you weren’t wearing.

Last Thursday, Tara Reid’s nipple made a surprise guest appearance on the red carpet at P. Diddy’s birthday bash in New York. It seems that as Reid went to remove her white fur wrap, the strap of her slinky, black dress came down, revealing her bare breast.

Reid continued to stand and smile for photographers, before her assistant approached her and pulled her fallen dress back up. As she was escorted inside, Reid wagged her finger at the crowd of photographers, warning that she better not see the photos anywhere.

Despite her earnest and sincere request that photographers keep the juicy photos of a half-topless Reid under wraps, her name and nipple were all over papers, popping up on Web sites and flashing on TV within moments.

But what I find most startling about this entire ordeal is that if it was cold enough to be wearing fur, wouldn’t someone be able to tell that their entire left breast was exposed to the cold? And furthermore, wouldn’t the vapid Reid notice the crowd perking up and the increase of flashing from photographers? Not unless she knew that cardinal rule of celebrity: sex sells.

I seem to remember when celebrities used to promote themselves by appearing at ribbon cutting ceremonies or subjecting themselves to the mindless banter of daytime talk shows. They may have even been one of the few, proud entertainers who earned the fame by doing quality work they care about. Now stars just sit back and let their bodies do the talking.

Fellow Hollywood party girl and blonde bombshell Paris Hilton, for example, began to consistently make headlines with the release of her now infamous sex tape. The steamy footage was conveniently released before the start of her televised adventures with pal Nicole Richie on Fox’s “The Simple Life” and catapulted Hilton into fame. Without the tape, I don’t think we’d be subjected to Hilton’s upcoming album or the addition of “that’s hot” to the American lexicon.

Besides Hilton and Reid, who could forget the ultimate “wardrobe malfunction” that took place during the Superbowl XXXVIII halftime show when singer Janet Jackson had her pierced, left nipple exposed by Justin Timberlake, just under two months before the release of her album “Damita Jo.” During the weeks that followed, I saw more of Jackson’s nipple than I did of my own.

Like a dog coming when told, a celebrity bares a little boob and the media falls right into place and eats it up. Album not selling so well? Dance your way out of your tube top in the midst of a popular night club. Is your movie going unnoticed? Just forget to put on your undies beneath that tiny mini-skirt. Wait and see, your name will be lit up in lights faster than you can say “Anna Nicole.”

When was it exactly that publicity became public titty?

It’s been a downward slope of shorter skirts, plunging neck lines and fabric becoming less and less opaque for a few years now. J. Lo’s revealing Oscar dress that once dropped jaws now seems Puritanical when compared to more recent celebs dropping trou. It’s getting to a point where seeing Reid’s nipple is about as surprising as seeing Britney Spears’ pelvic bones.

Now, one must ask, is it just the celebrities that have become racier or is it the taste of the American consumer that is no longer satisfied by Elvis Presley’s gyrating pelvis or Spears doing splits in a school-girl uniform?

Everyone knows sex sells, but while it used to be that just the idea of sex was enough to push a record up the charts or increase ticket sales for movies, the American consumer still wants more — more sweat, more tongue and lots more skin.

What’s more is that the Federal Communications Commission can make all the sanctions they want, but as long as horny young males still clamor for more tittillating material, celebs will find ways to slip a little nip to the camera.

But be warned, if celebs keep getting ecouraged to bare more and more, it won’t be long before former “Golden Girl” Bea Arthur is caught parading through Filene’s in a g-string and nipple tassles.

– Bobby Hankinson can be reached at [email protected]