The show's biggest fashion moment to date came a few weeks ago when Bree (Marcia Cross) tried to seduce her straying spouse clad only in a fur coat, pearls and a red lace La Perla bra and panty set. Bloggers on fan sites went wild, and a spokeswoman from La Perla says the $265 lingerie set has since sold out. The company does a lot of TV and film placement, she says, including the orange bikini Halle Berry wore in the last James Bond flick, but nothing as successful as this.

On the other end of the age spectrum is teen dream "The O.C." Now in its second season, the show has been buoyed by the personal style of its young stars Mischa Barton, whose relationship with the fashion house Chanel (they dress her for public appearances) translates into costumes for the show, and Adam Brody, whose signature geek chic (sweater vests over polo shirts) has trickled down to the racks at department stores.

A new subscription-based Web site (theocinsider.com) and a companion magazine launched last month offer fashion and makeup tips written by the show's staff, among other things. The site also sells clothes that the characters could wear. In the works for spring is a high-end apparel line from the Warner Bros. division responsible for the vintage-inspired Looney Tunes line.

" 'The O.C.' has a lot of impact on our readers," says Amy Astley, editor-in-chief of Teen Vogue. "After Mischa Barton carried a Chanel tote as her school bag, it was considered highly desirable. Of course, not everyone can afford Chanel, but the trend went away from the backpack to the tote anyway. It's also the impact of the actors themselves, like Adam Brody, with his Mr. Rogers cardigans. When we shot him for the cover of the magazine, we didn't change the way he was dressed at all."

Down at Raleigh Studios in Manhattan Beach, Calif., where "The O.C." is filmed, costume designer Karla Stevens is on an eight-day shooting schedule that begins with a shopping spree at Planet Blue in Malibu, Champagne in Redondo Beach, vintage stores Golf Punk and Wasteland in Hollywood, and Barneys New York "for the boys."

"What's great about a show like 'The O.C.' is that it's a whole lifestyle we're selling," she says. "With a rich community, everyone looks beautiful, drives beautiful cars, lives in beautiful homes and wears beautiful clothes. We have the opportunity, unlike other shows, to go over the top. We can look at what's coming off the runways and translate it into the characters."

The operative word may be "selling." When "Sex and the City" costume designer Pat Field put an enormous flower pin on Sarah Jessica Parker's lapel, it wasn't because she was partnering with a jewelry designer. But that kind of scenario could be coming to a TV near you soon.

"Sex and the City" didn't take advantage of licensed apparel and products until the last couple of seasons. But Lisa Gregorian, senior vice president of TV creative services for Warner Bros. Television, isn't going to make the same mistake. She's making "The O.C." into a brand, with interactive games, soundtracks and high-end apparel.

The "O.C." collection will be "aspirational," according to Karine Joret, who works in the Warner Bros. consumer products division. The line of clothing and accessories will be limited to 10 to 15 pieces, which will probably be introduced at a single boutique in L.A. and a single boutique in New York, she said.

This season, Seth's clothes have been simplified. "He had a few too many Penguin polos," says Stevens. "Summer went through a whole sweatsuit stage, but we are doing more tweed jackets on her. We're doing a lot of sparkle and brooches on Mischa, which has become a major trend on the street,"

The outsider from Chino, Calif., Ryan (Benjamin McKenzie) lands in the wealthy community by accident. "Ben is concerned from a character standpoint that he stays close to home, and he wants that blue-collar vibe," Stevens says. "But we like to incorporate Orange County because that's where he is now. We've tried to subtly do that with more color. He'll wear a vintage shirt with a wife-beater underneath. The wife-beater is his staple, along with his black Caterpillar boots. We were thinking this season of doing a new shoe for him, and I can't tell you how many we brought in from Prada to Skechers. But we just gave up," says Stevens, who says she learned from working with Robert De Niro on "Jackie Brown" that actors often build their characters from the shoes up.

Stevens puts together 60 to 100 costumes per episode. She also writes a weekly column for theocinsider.com, which begins, "Hello fans and fashionistas!" A recent missive discussed accessorizing with pearls, round-toe pumps, tweed caps and Coach clutch bags.

"Desperate Housewives" has fashion potential too, says Teen Vogue's Astley. "I think their hotness may have hit them by surprise. But the leading ladies are attractive, and they are already somewhat identified by their clothes." The influential L.A. boutique Kitson has decorated its windows in the campy style of Wisteria Lane and will soon sell "Desperate Housewives" T-shirts.

Although Gabrielle's (Eva Longoria) Juicy Couture tracksuits may scream Southern California, "Desperate Housewives" is set in a fictitious state. "I work hard at making the clothing accessible to anyone in America but not specific to any region."

Adair's schedule begins on Sunday afternoon, when she hits Boca, Whispers and the vintage store Gift Garden Antiques, all in Pacific Palisades. She shops brands such as Theory, Catherine Malandrino, Velvet, Maggie Barry and Nanette Lepore with each character in mind.

"I try to think what they would buy if they were out shopping," says the designer, who works with a team of nine. By the end of the eight-day shooting cycle, she has shopped for, altered and fit 50 to 100 costumes, not counting the ones for extras. "A lot of pieces I re-dye or cut up. It is design because it's how you mix and match things, and that's what women do in real life."

Bree, the consummate perfectionist, always has to match. Gabrielle is more fashion-forward. Edie's style is similarly sexy. Part of the way I differentiate between their characters is by the actresses. They both look great in Frankie B jeans, for example, but Nicollette (Sheridan) is quite tall and has very different body language." Susan (Teri Hatcher) has a more eclectic, mismatched style, while Lynette (Felicity Huffman) is more plain. (She's often dressed in a man's shirt.)