Star Tracks - Thursday, September 18, 2008

It's been a whirlwind week for Jennifer Lopez! Days after participating in the Malibu Nautica Triathlon and throwing a surprise 40th birthday party for husband Marc Anthony in New York City, the singer hits the streets Wednesday in Saint-Tropez, France.

Mariah Carey can always count on the support of husband Nick Cannon. The attached-at-the-hip couple were spotted making a cozy exit Wednesday from Barneys New York in the Big Apple.

Renée Zellweger shows off her fit form in a designer Carolina Herrera dress at a special screening Wednesday of her movie Appaloosa at the Academy Theatre in Beverly Hills. Filming the Western was a blast, the actress tells PEOPLE, "Men in hats and chaps on horses everyday is not a bad day at work."

Charlize Theron shows her support for boyfriend Stuart Townsend Wednesday at a New York City screening for his writing-directorial debut, The Battle in Seattle. Theron and Andre Benjamin (Andre 3000 from rap duo OutKast) star in the drama about the street protests that shut down the 1999 meeting of the World Trade Organization.

Denzel Washington – with an oversized poster of little Denzel behind him – is the movie star in the middle of a flock of kids Wednesday at a launch event in Washington, D.C., for the Boys amp Girls Clubs of America's new Be Great campaign. The Oscar winner, who is the national spokesman and a Club alum, is encouraging people to volunteer at their local clubs.

Tom Cruise and Katie Holmes are surrounded by a throng of fans Wednesday after the final dress rehearsal for her Broadway show All My Sons. Previews for the Arthur Miller revival – which opens Oct.16 – begin Thursday.

After walking the Henry Holland runway show Thursday during London Fashion Week, model Agyness Deyn is spotted off the runway in one of the designer's dotty creations while leaving a party celebrating his show.

Glamour girl Taylor Momsen gets tongues wagging on the New York set of Gossip Girl while keeping company with her pet pooch during a break from filming Wednesday.

Naomi Campbell – who recently revealed her battle with infertility – shares the catwalk Wednesday with 18-year-old American model Chanel Iman. The two hit the runway at Campbell's annual Fashion for Relief show, this year benefiting the White Ribbon Alliance (which aids pregnant women and newborns) at London's Natural History Museum.

Nick Jonas (right), who received a new puppy from his family for his 16th birthday, hangs with his older bros Kevin (left) and Joe during a shopping trip Wednesday to a Beverly Hills Big 5 Sporting Goods store.

She's got disco fever! Decked out in 1970s attire, Prince William's longtime girlfriend Kate Middleton is ready to boogie-oogie-oogie for charity as she arrives Wednesday to the Day-Glo Midnight Roller Disco, a fund-raising event she hosted at London's Renaissance Rooms club to aid the Children's Hospital in Oxford, England.

After announcing her involvement in a new text-messaging charity campaign, Nicole Richie gets back to personal commitments Wednesday, clinging to her trusty cup of coffee as she continues her court-mandated classes at a local driving school in North Hollywood, Calif.

Walking the streets of New York is a contact sport for Charlize Theron! Following her appearance on The View Wednesday, the actress reaches out to a fan waiting outside of her hotel.

Is caffeine her secret weapon on the dance floor? Kim Kardashian – who has been blogging about preparing for Dancing With the Stars – gets a little pick-me-up Tuesday with a Coke Zero and some snacks from Cuvee Wine amp Food in Beverly Hills.

Sporting a T-shirt covered with her name and the lyrics to her single, "Stars are Blind," Paris Hilton keeps her tan in check Wednesday with a trip to the Portofino Sun Center amp Spa in Beverly Hills. Next up for the heiress: a scripted series, with Ryan Seacrest.