Remember when all any big model really aspired to was a serious acting career? For Andie MacDowell, Rene Russo, Isabella Rossellini and Geena Davis, it worked out.

Classic Isabella.

For Cindy Crawford, it hasn’t been so easy. But Cindy may be luckier than she realizes because every star in Hollywood apparently wants to follow her into modeling.

Actors and actresses, from ingenues to Oscar nominees, are showing up in conspicuous fashion and beauty ad campaigns, in print and television. And that’s not all — Hollywood habitues are suddenly so anxious to be associated with the New York Fashion Flock, some have moved from comfortable front-row seats at shows to actually walking the runways.

Fashion designers have always been smitten by Hollywood, by movie stars, by directors, by the international exposure afforded by the Oscars. But it wasn’t long ago that advertising of any kind was considered “beneath” most stars. Their agents warned that if they were too conspicuous in commercials or print ads, audiences wouldn’t pay to see them on the big screen. Hollywood logic has it that Cher stopped being a movie draw when her informercial came directly into bedrooms night after night.

Then came the supermodels. They got the press, the glamour, the cachet, the boyfriends, the exposure, the lifestyle and, in some cases, the money that movie stars are used to. Designers like Karl Lagerfeld and Isaac Mizrahi announced that Linda, Claudia, Cindy and Naomi were much more exciting and beautiful than the current crop of screen stars, who were making the scene in ponytails, flowered dresses and combat boots.

“Everything’s cyclical,” claims Cari Ross, vice president of publicity for Susan Geller & Associates, which represents Anjelica Huston, Meg Ryan, Claire Danes and Fran Drescher, among other stars. “There used to be a big music biz crossover with Hollywood. Now it’s fashion. Next year, it will be something else. I think it had a lot to do with Isaac [Mizrahi] doing a movie — a really good movie — and the attention all those Calvin Klein ads have gotten. Stars want to horn in on the cultural trends.”

Melanie Griffith and Halie Berry are doing Revlon, Elizabeth Hurley is the Estee Lauder woman; Gabriel Byrne was featured in a Donna Karan campaign; Tim Roth is in Prada’s ads; Juliette Lewis did a commercial for Guess; Fran Drescher and Tina Turner are in Hanes campaigns; Juliette Binoche is the Lancome face; Madonna did a Versace campaign; Natalie Portman has appeared in Isaac ads — with actress Diane Lane now shooting Mizrahi’s fall collection campaign; actresses like Claire Danes and Molly Ringwald walked Cynthia Rowley’s runway; Elisabeth Shue is in the current Gap campaign, and the grandmother of all the new pitch people, Elizabeth Taylor, has been starring in her own ads since she got into the fragrance business. But the big clincher came last week with the news that two of Hollywood’s biggest stars, Demi Moore and Bruce Willis, will be the only models in Donna Karan’s fall collection print campaign, to be shot by Peter Lindbergh.

Even the children of celebrities are getting into the act In a $25 million fall campaign for his new women’s line and fragrance Tommy Hilfiger will feature daughters of the famous, including Ivanka Trump and Kidada Jones (daughter of Quincy Jones), and possibly Nicky Poitier, daughter of Sidney Poitier.

Shoe designers are doing the star circuit, too. Diego Della Valle is pursuing some major names for a Hollywood “couple” campaign to be shot by both a celebrity photographer and a fashion photographer. The campaign is to be launched in the fall.

While Hollywood’s fascination with fashion is a relatively new phenomenon, fashion’s fascination with Hollywood isn’t. Back in 1968, Blackglama launched its “What Becomes a Legend Most?” campaign, starring Bette Davis, Lauren Bacall, Barbra Streisand, Judy Garland and Melina Mercouri. Scores of stars went on to be photographed in Blackglama mink coats.

The incentive for those stars was a mink coat; today’s celebrities have their own reasons for “selling out”

“Initially, I think actors think it’s money for old rope [pocket money] to get an advertising/beauty contract,” says Elizabeth Hurley. “It sounds easier than making movies or performing in a play. Actually, it’s incredibly difficult to concentrate for long periods of time on a still image and it is exhausting — quite as much as filming. But for me, it seems to have been a good career move: It ups your visibility, which makes you more marketable. So far, so good.”

“It’s a way of exposure without telling your life story to a reporter all over again,” says Liz Rosenberg, spokeswoman for Madonna. “Fashion people are rock stars now; they’ve become big celebrities, and now they’re all in the same club. Doing ads doesn’t have the same stigma it once had.

“When Versace approached Madonna,” Rosenberg continues, “she was advised it might be tacky to do the ads. But all the feedback we’ve gotten is how beautiful she looked. If it’s a clever ad with a great photographer, why not? Basketball stars do very hip commercials and acts. You can have control over an ad shoot, but not an editorial one, and that’s what artists want. Plus, five or 10 photos in the major magazines is always good — Warner Bros. Records is never going to take out an ad campaign that big. For the right product, it can enhance your image.”

Many in Hollywood concur that the real fashion/movie crossover kicked in several years ago when Giorgio Armani began to pursue stars as mannequins. “His aggressiveness in the marketplace convinced the other designers to go for it,” says one top Hollywood public relations executive.

Versace and Valentino followed, and for this year’s Oscars, Calvin Klein, Isaac Mizrahi, Badgely Mishka, Donna Karan, Ralph Lauren, Dolce & Gabbana Richard Tyler, Escada and Pamela Barish all courted the nominees by hiring public relations reps to go get ’em and dress ’em. And word has it Gucci and Prada are right now looking to hire “star coordinators” for their West Coast offices.

Some stars need all the help they can get.

“Just because they’re actors doesn’t mean they know how to dress,” says Cari Ross. “Claire Danes decided to do Cynthia Rowley’s runway show because she just loves her clothes — and if you have to look good all the time, it’s easier to do with a de Drescher’s a different case; she really knows her own look and doesn’t need help. She did the Hanes ads because they paid her a lot of money. But if the campaign wasn’t classy, if the photographer wasn’t first rate, if the concept wasn’t cool — we would have told her not to do it.”

According to Anne Jardine, vice president of marketing at Hanes, “Fran was perfect. She has such humor; that was great for Smooth Illusions. We had good increases in sales when she appeared.”

“Remember,” says Pamela Barish, who has dressed many a Hollywood celeb and used Rosanna Arquette tints month as a model on her show’s invitation “it’s not a one-way street. Yes, designers get exposure — but actors get a glamorous image and free clothes. We enhance their image. It’s a fair exchange.”

Star photographers, who often shoot celebrities for editorial pages, have certainly helped seduce the stars into advertising. Greg Gorman, for example, started shooting the LA Eye works campaign with famous faces in frames — with the tag line, “A facets like a work of art: It needs a great frame” — in 1982. Since then, he has shot Drew Barrymore, Pee Wee Herman, Ben Kingsley, Mickey Rourke, Sharon Stone, James Woods, Melissa Etheridge, Sir Ian McKellan and lots of others for the ongoing campaign. “One day, Racquel Welch called up and said she loved the campaign,” says Ruth Handel, LA Eyeworks’ director of advertising. “About an hour later, she was over at Greg’s studio shooting the next one.”