Some girls just have stamina. Like the model Jessica Stam, who flew out to L.A. last weekend for a job, came back to New York for 24 hours on Monday, hightailed it to Paris for another job on Tuesday, and returned to Manhattan early Wednesday morning to run some errands before slipping into a fancy dress and meeting a few dozen friends at Nobu Next Door to celebrate her 22nd birthday. "I guess I should be tired," she said, sitting between pals Michelle Trachtenberg and Tara Subkoff. "It's just birthday adrenaline." Stam's entrance was classy—she arrived just a few minutes late (as one does on one's birthday) and sauntered to her table. Then her buddy Jen Brill started heckling: "Is that the supermodel Jessica Stam? She's sexy!" she yelled, much to the amusement of the other diners. A little bit of blushing from the lady of honor, and then the casual affair got underway, with Leigh Lezark and Mary-Kate Olsen anchoring one end of the table, and Stam's buddies Chrissie Miller, Jared Seligman, and a couple of guys from the band the Virgins on the other. After cake, it was on to Lit, where a bigger posse continued the celebration.