05/14/2009 at 03:00 PM EDT
cast reunion alert! Kate Walsh
threw a birthday party for Sally Ann Brooks
, her good friend (and onetime Grey
's guest star), at BoHo, a new gastropub in Hollywood. And T.R. Knight
and Justin Chambers
were on hand to celebrate with their significant others. While Chambers stayed near his wife Keisha
, Knight was equally affectionate with boyfriend Mark Cornelsen
and "let [him] take a seat on his lap," a guest tells us.
and Taylor Lautner
are still hanging out – and dining out. The duo recently headed to the Keg Steakhouse & Bar in Vancouver, where they were "very sweet [and] sat very close to each other," a witness says. The two giggled over appetizers before leaving through the back door, holding hands.
Just returned from Paris, Lindsay Lohan
was in good spirits during her night out at Bardot Hollywood. The starlet sat in a center booth on the patio, drinking and chilling with her group. "At one point she then asked that they be moved closer to the deejay booth," says an onlooker. Also there: a super-sweet and smiling Kelly Osbourne
, who was guest deejaying. Escorted by fiancé Luke Worrall
, she kept the crowd energized while her beau never left her side.
's Steve Carell
, grabbing a solo lunch at the Cat & Fiddle pub in Hollywood. The funny guy grabbed a table in the courtyard, ordered a sandwich and soda and read the newspaper he brought with him.
, doing pull-ups at Equinox in West Hollywood. Madonna's ex politely chatted up "a pretty petite blond in her twenties in bright yellow pants who was working out nearby," an eyewitness says.
Model and deejay Alexandra Richards
, sunbathing at the Montauk Yacht Club Resort & Marina in Montauk, N.Y., and sipping a spicy Club Margarita.
By DAVID CAPLAN, JENNIFER GARCIA, CHRISTINE KILPATRICK, MARISA LAUDADIO and KRISTEN MASCIA
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