If you were on the East End of Long Island on Saturday, chances are you were either at a party or in a traffic jam en route to one. Over in Bridgehampton, the Mercedes-Benz Polo Challenge drew a trio of Hollywood pony fanciers in the form of hostess Heather Graham, Chloë Sevigny, and Christina Applegate, who said, "I came to live out my Pretty Woman fantasy of replacing the divots." As is traditional at these things, guests were more focused on the bar than the game. Stacey Bendet, Oprah's BFF Gayle King, and DJ Sky Nellor beat the heat with iced tea courtesy of Gold Peak, one of the event's many sponsors.

Meanwhile, in Water Mill, bargain hunters, including Carey Lowell, Christy Turlington, and Molly Sims, hit the ninth annual Super Saturday event hosted by Kelly Ripa and Donna Karan (who later showed up as a guest of honor at the Rush Foundation's Art for Life benefit at Russell and Kimora Lee Simmons' house). Sales of clothing and accessories donated by 20 top designers helped to raise over $2 million for the Ovarian Cancer Research fund. "I bought all Chanel," said Fabiola Beracasa. "I almost had to hurt someone to get this suit for my mom."

Toward dusk, Andrew Saffir welcomed Howard Stern, Alexandra Wentworth, and Reed and Delphine Krakoff to his Cinema Society screening of The Night Listener. After the movie, guests headed to Jerry Della Femina and Judy Licht's beachfront property for a Serena Bass-catered dinner and s'mores on the beach. Ione Skye, Carla Gugino, and Samantha Mathis sat around the bonfire, mingling with the film's star, Toni Collette, and director, Patrick Stettner. "I grew up in New York; I don't do s'mores," joked the auteur. Collette, for her part, grew up in Australia, and at 1 a.m., was in the pool, frock and all, sipping chilled rosé.

— Sarah Cristobal