Star Tracks - Friday, September 29, 2006

Janet Jackson enlists some help from rapper pal Nelly for a performance Friday morning on The Today Show. The pair collaborated on the single "Call On Me," off Jackson's 20 Y.O. album.

A day before reports emerged that Eva Longoria and her boyfriend of nearly two years, Tony Parker, have split, the Desperate Housewife puts her best face forward as she meets the press after leaving a Beverly Hills salon on Thursday.

Though Harry Morton recently told TV's Extra that he and Lindsay Lohan were taking a little breather, they're still talking: The couple met for lunch Thursday at The Ivy in Los Angeles.

Hip-hop mogul and fashion entrepreneur Sean "Diddy" Combs ignites the runway Thursday at Macy's Passport Gala fashion show and charity bash in Santa Monica, which raised money for HIV/AIDS research.

Birthday girl Hilary Duff saddles up for another year! The singer-actress, who turned 19 on Thursday, celebrates her special day with a horseback ride through the canyons outside of Los Angeles.

Everything's coming up roses for Dancing With the Stars's Vivica A. Fox, who continues her dance fever in Las Vegas on Thursday, where she helped celebrate the 25th anniversary of the classic showgirl revue, "Jubilee."

About last year's PEOPLE's Sexiest Man Alive! Matthew McConaughey keeps showing off his hard-bodied assets – and a love for bandannas! – while working out in Santa Monica on Wednesday.

After flying overseas to support sis Ashlee in her West End debut in Chicago, Jessica Simpson gets back to her home turf – and back to work – in Los Angeles on Thursday. The actress is scheduled to appear on the Tonight Show Friday to promote her comedy Employee of the Month, which opens Oct. 6.

After being charged with a DUI stemming from her Sept. 7 arrest for "driving erratically," Paris Hilton switches gears – to a standard two-wheeler – during her visit to Amsterdam on Thursday.

Nicole Richie, who recently celebrated her 25th birthday, keeps her cool while out in Beverly Hills on Wednesday.

Even without his usual cycling companions Lance Armstrong and Matthew McConaughey, Jake Gyllenhaal keeps up his training, dodging traffic in New York City's East Village on Thursday.

Michelle Branch shows that underneath it all she's a cowgirl at heart at a benefit concert to support breast cancer awareness at New York City's's Crobar on Wednesday, where she performed with pal Jessica Harp as the country duo The Wreckers.

Mayor Michael Bloomberg and Robert De Niro show Rome's Mayor Walter Veltroni (left) some Big Apple hospitality during a meeting Thursday to broker a partnership between the cities' two film festivals at City Hall. Bloomberg, who recently proposed a ban on trans fats in the city's restaurants, also praised the actor-restaurateur for not using artificial oils at his eateries Nobu and the TriBeCa Grill.

Birthday girl Avril Lavigne, 22, gets escorted out of Hyde in Los Angeles on Wednesday night by her musician husband, Deryck Whibley, after an impromptu autograph session seemed to put a damper on her celebration.

Alicia Keys enjoy the sights in Florence, Italy, on Wednesday. Before her vacation, though, she was hard at work, contributing the song, "Almost Everything Is Boinga Here," and voicing an alien character for the animated show The Backyardigans, airing on Nick Jr. Oct. 9.

Desperate Housewives star Nicollette Sheridan proudly shows off a potato-studded trophy – clearly an honor – on the show's set Wednesday.