Courteney Cox and David Arquette
11/30/2010 at 05:00 PM EST
Though they reunited
for a family bowling outing in November, on Monday, it was all business for Courteney Cox
and David Arquette
as they lunched together with three associates at Morton's the Steakhouse in Burbank. They arrived and left separately, though Arquette kissed his estranged wife on the cheek when she entered the restaurant. "They were very cordial and friendly," an onlooker tells PEOPLE.
Before the Parisian premiere
on Monday, Brad Pitt
enjoyed a little alone time in the City of Light. The actor slipped into Chez Prune restaurant along the city's Canal Saint Martin, before popping into a nearby photo laboratory that specializes in silver prints.
and Katie Holmes
boned up on their historical studies recently as they enjoyed a tour of the California Science Center in Los Angeles. The pair viewed the Mummies of the World display, presented by American Exhibitions, and were "completely down-to-earth and very sweet with one another," a source tells PEOPLE.
threw a party for his manager at New York's Hotel Griffou, complete with pear rosemary juleps and buffalo turkey wings from chef David Santos. West and his entourage arrived around 9 p.m. and sat in the private wine vault, where they partied the night away. Before the celebration ended, the rapper broke into a happy birthday freestyle – then left a big tip on his way out.
Following Monday night's Gotham Independent Film Awards in New York City, stars turned up to party at Wall & Walter inside the Andaz Wall Street hotel. Twilight
's Peter Facinelli
was the first to arrive, and danced by himself until his pals joined him. Mark Ruffalo
noshed on mini-cupcakes while chatting with director Darren Aronofsky
, and Annette Benning
could not get enough of chef Maximo Lopez May's salami appetizer.
By KRISTIN BOEHM, JENNIFER GARCIA, LINDA MARX and PETER MIKELBANK