Marc Malkin

Justin Sullivan/ Getty Images

AT YOUR SERVICE: Matthew McConaughey and Jon Bon Jovi, joining first lady Michelle Obama, Gov. Arnold Schwarzenegger and Maria Shriver in San Francisco for the Entertainment Industry Foundation's launch of its new Nationwide Service Initiative.

HOMEBODY: Twilight star Cam Gigandet, shopping at Anthropologie in Beverly Hills with girlfriend Dominique Geisendorff.

HOME SWEET HOME: Hugh Hefner, ordering a bottle of tequila for the slew of Playmates surrounding his table at Hollywood hot spot MyHouse.

What did we catch Josh Duhamel doing the other night just before the big Hollywood premiere of Transformers? Keep reading to find out...

SEMPER FIDELIS: Josh Duhamel, having a drink at the Whiskey Blue at the W Los Angeles-Westwood hotel before the Transformers premiere. Before leaving, he bought a group of Marines at the bar a round of tequila shots.

IN THE RING: Chace Crawford, having dinner at First Food & Bar at the Palazzo Las Vegas before heading to the Pearl at the Palms for the Ultimate Fighter UFC finale.

ISLAND HOPPING: Grey's Anatomy star Justin Chambers and wife Keisha Chambers, stopping by the Maui Film Festival's Opening Night Starry Night MoonDance Party at Tommy Bahama's.

SELF-CENTERED: AnnaLynne McCord, True Blood's Sam Trammell, Jillian Michaels and Aimee Garcia of NBC's upcoming Trauma, mingling at the Self magazine party at L.A.'s Sunset Tower Hotel.

KARAOKE ROUND: Jamie Foxx, jumping on the couch, singing his tune "Blame It..." when the DJ played it at Skybar in West Hollywood.

DATE NIGHT: Eva Mendes, dining on truffle pasta, while on a double date at Il Sole in West Hollywood with boyfriend George Gargurevich and another couple.

SUMMERTIME SIPPIN': Michelle Trachtenberg, sipping on an Alizé champagne cocktail at the Kick Off to Summer Event at the Byron & Tracey Salon in Beverly Hills.

PARTY STARTERS: Lance Bass, Cheryl Burke and Ashley Greene, hanging out with friends at new Hollywood nightspot Madame Royale.

JERSEY GIRL: Hills comeback queen Kristin Cavallari, dancing to tunes spun by Samantha Ronson at club Mur.mur at the Borgata Hotel Casino & Spa in Atlantic City.

SHOP GIRL: Sanaa Lathan, shopping at Live! on Sunset in West Hollywood.

DIRECTOR'S CUT: Quentin Tarantino, chowing down at Gardens of Taxco in West Hollywood.

—Additional reporting by Dahvi Shira and Giselle Ugarte

________

Get more Marc on Twitter @marcmalkin