Star Tracks: April 30, 2004 - Britney Spears

Britney Spears spends one of her last precious days off from the sold-out Onyx Hotel world tour relaxing on a beach in Pacific Palisades, Calif., with two scruffy friends. (The human is dancer Kevin Federline.)

Mariah Carey gains her sea legs – and shoes – as she disembarks the catamaran Scoobi Too to spend the night on St. Bart's.

Christina Aguilera flirts with the camera while filming a Virgin Mobile commercial that's been deemed too hot for American television. The singer, who was paid more than $1 million and arrived six hours late for her shoot, apparently gets naked in what some reports are calling the "sexiest ad ever" for the British mobile phone company.

Mary-Kate (left) and Ashley Olsen share everything – even their shiny new star on the Hollywood Walk of Fame. The girls, whose movie New York Minute opens May 7, are the first twins ever to receive the honor.

New York-born "Milkshake" singer Kelis sauces up the launch of designer Matthew Williamson's first flagship store in London.

Like the Hollywood royalty she is, Oscar winner and event co-chair Renée Zellweger shows off the elegant train of her gold Carolina Herrera gown at the Metropolitan Museum of Art Costume Institute Benefit Gala in New York. Calvin Klein, Vogue editor Anna Wintour, Jerry Seinfeld and Hugh Jackman joined Zellweger in celebrating the new exhibition Dangerous Liaisons: Fashion and Furniture in the 18th Century.

Imitation of Christ designer Tara Subkoff and Lost in Translation star Scarlett Johansson put on their most fashionable faces at the Costume Institute Gala afterparty in New York.

Denzel Washington turns the tables on red-carpet reporters and grabs a microphone from an interviewer at the Los Angeles premiere of his crime thriller, Man on Fire.

Sandra Bullock once again dolls up as undercover FBI Agent Gracie Hart, this time hitting Las Vegas Boulevard in Sin City dressed as a cowgirl to film the sequel to her 2000 hit Miss Congeniality.

Without her signature glasses, SNL's Tina Fey looks more Hollywood than funny girl as she parties with Jonathan Bennett and Lindsay Lohan at the L.A. premiere of their film, Mean Girls. Fey wrote the new comedy's screenplay, which has Lohan falling for an ex-boyfriend (Bennett) of a popular rival.