At last night's Cinema Society/Allure screening of her movie Margot at the Wedding, Nicole Kidman put on a brave face (and a black Jil Sander overcoat) despite being sick. She apologized, with impeccable politesse, for not shaking hands ("I don't want to infect you"), and kept her arms tightly wrapped around her. "I'm freezing," she said. But a healthier Nicole emerged from her tales of derring-do on the set. "I've been doing most of my own horse-riding," she said of her work on the upcoming Baz Luhrman epic, Australia. "Just recently we ran with over 1,500 wild horses, and we were riding with them. And that's pretty hair-raising." Wasn't she worried about falling? "I just didn't think about it," she said. "I feel confident on a horse." Kidman explained that she's been riding since she was 3. Still, Kidman in a stampede of hundreds of wild stallions? That's like throwing a toothpick into a jet engine. Wonder who insured that? —Darrell Hartman