Out on the dance floor, the CSI cast cut a rug (but, surprisingly, didn't examine the fibers). Elsewhere, Hilary Swank took a moment to introduce her mom to Marcia Cross's mom. And so it went, through the night, with breaks for crab cakes or hazelnut dacquoise.

The occasion? The official gala, cohosted by PEOPLE and the Entertainment Industry Foundation—a leading Hollywood charity—that follows the Screen Actors Guild Awards. The Feb. 5 party drew 1,200 guests to a 12,000-sq-ft. tent decorated with 44,000 polka dots (think '60s-era Dior). PEOPLE and EIF also jointly donated $100,000 to the SAG Foundation, which helps actors in need. For EIF, it's a way to thank actors who help with their charities; for PEOPLE, it's a way to show appreciation for an industry we cover every week.

Also: It's just fun to throw a party.