The classic 1955 film The Seven Year Itch includes one of the most unforgettable moments in Hollywood history-Marilyn Monroe mincing across a Manhattan subway vent as a wild gust of wind billows her white halter dress in the air. Fifty-one years later, that dress remains a symbol of glamour and sex appeal, proving the power of fashion in Hollywood.

Now more than ever, a celebrity’s image can make or break a career. To whit: red-carpet appearances by Elizabeth Hurley and Jennifer Lopez, both in Versace dresses, put these femmes fatales on the fashion radar. With the stakes so high, stars will pull out all the stops to ensure they always look flawless, but their seemingly effortless chic is usually a strategically crafted persona created by a handsomely paid stylist.

When celebrities want to reinvent their image, they hire stylists such as Jessica Paster and Phillip Bloch. While these fashion pros have transformed the images of such stars as Nicole Richie, some celebs, like Mariah Carey, are still one miniskirt away from a fashion meltdown.

Queen Latifah

In the early ’90s, Queen Latifah was known for her Afrocentric style and female-empowering lyrics, but her performance in Chicago marked her crossover into Hollywood. With the help of celebrity stylist Susan Moses, a former plus-size model, Latifah never fails to stun audiences in garments that complement her full figure. For this year’s Oscars, she looked ravishing in her strapless Carmen Marc Valvo gown complete with gorgeous hair and makeup. All hail the Queen!

Mariah Carey

Last year, the Grammy-winning singer emancipated Mimi and hired André Leon Talley, editor-at-large of Vogue, to help lock up her Daisy Dukes. Although Carey has recently traded in her stripper getups for designer duds from the likes of Marc Bouwer, the darling diva still managed to bring the House of Coco down! At this year’s Golden Globe Awards, the pop starlet wore a skin-tight plunging gown designed by Chanel’s Karl Lagerfeld. Unfortunately, Carey looked more crass than couture. While she boasted to the press about wearing Chanel, the luxury company attempted to dodge reporters’ queries. Despite Carey’s best intentions, her image may never evolve like the proverbial caterpillar into a butterfly.

Nicole Richie

Richie made her”acting” debut behaving like a Beverly Hills brat on the hit TV series The Simple Life. Her slovenly appearance mirrored her personality, but when her friendship ended with co-star Paris Hilton, Richie wasted no time hiring celebrity stylist Rachel Zoe to give her a much-needed image makeover. For Zoe’s signature look,”boho chic,” she charges about $6,000 a day. Richie has now re-emerged as skeletal, albeit wearing designer gowns and Jackie O-inspired sunglasses. Not only has Richie refined her outward appearance; it seems the grande-dame makeover is also working on the inside — she has cleaned up her bad behaviour.
The Olsen twins

Their net worth is an estimated $300 million, they own a clothing line and Ashley interned with fashion designer Zac Posen, so why do the Olsen twins continue to top worst-dressed lists? Whether it’s Mary-Kate in L.A. or Ashley in New York, the twins layer dirty-looking, ripped jeans, baggy sweaters and grungy footwear. Some call their style”bobo,” while others call it”hobo.” Surprisingly, their”original” style helped them land a modelling gig with Badgley Mischka. In the designer’s ads the sisters wear glamorous gowns, but they still look like they ransacked their mom’s closet.

Chloe Sevigny

Her unconventional beauty matches her independent style. The thrift-store fashionista has always eschewed trends and stylists. Whether she’s wearing designer gowns or a vintage-chic ensemble, Sevigny adds a unique twist. At the 2006 Golden Globes, she turned heads with a purple scrunched-taffeta dress with balloon sleeves. Despite strong connections to the fashion house Imitation of Christ, Sevigny insists her true passion is acting.Sienna Miller

Crowned the”princess of boho chic,” Miller is known for her signature floaty tunics, ethnic baubles and peasant skirts. The actress created boldface buzz when she cut her trademark tousled tresses into a sassy bob for her role as Edie Sedgwick in the upcoming film Factory Girl. Her love life — with philandering Jude and pretty-boy Hayden — generates as much ink as her occasional fashion slip-ups. Case in point: her love affair with ’80s leggings and the pink puff dress she wore to last year’s Moët & Chandon Fashion Tribute in London.

Britney Spears

Remember the days when Spears lit up the red carpet in sexy designer ensembles? Since marrying Kevin, it seems that Spears has lost her way and her fashion sense. The new mom is boycotting bras and has been photographed walking barefoot in gas-station restrooms. And what’s with those baby tees and trucker hats with provocative language written on them? The press is totally perplexed by her drastic fashion decline, calling her an”over-the-hill Lolita” and begging her to hire a stylist. Even Christina Aguilera, who also has a dubious fashion sense, says Spears has let herself go. Now that’s bad.

Fergie

She’s the lead singer of The Black Eyed Peas, and, like the group’s music, Fergie’s style tries desperately to be eclectic but comes across as chaotic and confused. One minute she’s dressed in a baseball cap and sportswear, the next she’s shakin’ her hump in bootie shorts. The tragic part is that the wannabe diva really tries to look elegant but somehow always looks like she’s going to a basement party in Brooklyn. A stylist could help Fergie find a look that combines her edge with a touch of class.

Renee Zellweger

Carolina Herrera is famed for her custom-made gowns, so it’s no wonder that actress Renée Zellweger wants to wear them. She wore a red embroidered chiffon Herrera gown at the 2003 Oscars and switched to a white strapless number for the 2004 Oscars. She even wore Herrera to her beachside wedding. While she looked stunning, in the words of Simon Cowell,”It’s just safe.” Her quickie marriage and even quicker divorce from country singer Kenny Chesney might be the most spontaneous thing Zellweger has done in a while.

Charlize Theron

There is no denying that Theron is a breathtaking beauty, but her style (which is influenced by her stylist, Lisa Michelle Boyd) is quickly shifting from graceful to”Wow! What was she thinking?” At the 2006 Oscars, she tried shaking things up with a beehive updo and an overly architectural Dior gown complete with supersize bow. While some observers gushed, most guffawed at its over-the-top proportions.