Star Tracks - Thursday, Aug. 9, 2007

He may be on the fence about endorsing a presidential candidate in the '08 elections, but Leonardo DiCaprio wholeheartedly supports one cause – saving the environment. The actor proudly stepped out for the L.A. premiere for his new documentary, The 11th Hour, on Wednesday.

Hilary Duff and N.Y. Islanders hockey player Mike Comrie share a little action off the ice while spending a day together in Los Angeles on Wednesday. The pair have been spotted together recently, going out to dinner and hitting L.A.'s hot spots.

What better way to declare "we're together" than with identical outfits? Melanie Brown and her music producer husband Stephen Belafonte arrive at Long Beach Airport Wednesday after a weekend in Miami. The pair recently confirmed that they secretly wed in Las Vegas on June 6.

The Hills stars Lauren Conrad and Audrina Patridge make a glamorous entrance Wednesday at the third season premiere of their MTV reality show at the LG House in Malibu. Earlier, Conrad's former roommie Heidi Montag said she didn't think they'd ever be friends again. Conrad agreed: "People come in and out of your life, and that is life," she told PEOPLE.

Kate Bosworth makes quite an entrance at the The 11th Hour premiere in her one-sleeved dress by Jil Sander Wednesday night.

With no airline controversy on this trip, American Idol runner-up Clay Aiken makes a turbulence-free arrival at his New York City hotel on Wednesday.

Paris Hilton gets some face time with one of the seven Chihuahuas she owns – newest pup Jimi Hendrix – at her Malibu beach house on Wednesday.

Newly engaged Ivana Trump teaches Anne Hathaway a few moves on Wednesday during a glittering birthday bash for jeweler Fawaz Gruosi in Porto Cervo, Italy.

After celebrating son Maddox's sixth birthday over the weekend, Angelina Jolie is back in action Wednesday, filming Wanted in the Windy City.

With his status still in question, David Beckham suits up for a practice run Wednesday in Washington, D.C., where his team, the L.A. Galaxy, is scheduled to play against the D.C. United on Thursday night.

Gracing the September cover of Stuff magazine, Ivanka Trump gives a sneak peek of her upcoming photo spread during a luncheon in her honor Wednesday at Primehouse in Chicago.

Country star LeAnn Rimes swings into acting mode Tuesday on the Atlanta set of her film debut, Good Intentions. The singer previously honed her dramatic chops playing the role of Connie Francis in an episode of the NBC show American Dreams.

Time to crack out the sunscreen! Sienna Miller gets more than a little sun-kissed while relaxing with pals on a beach in Ibiza, Spain, on Wednesday.

And she'll dance if she wants to! Singer Kat DeLuna, who started a summer dance craze with her song "Whine Up," celebrates the release of her album 9 Lives at New York hot spot Marquee on Tuesday.

To listen to DeLuna's new tunes, go to PEOPLE en Español.

Following a visit to London, Liv Tyler is back to work on the Toronto set of The Incredible Hulk on Wednesday. The actress plays Betty Ross, the only woman the Hulk's alter ego Bruce Banner has ever loved.