Extravagant and block party are words that rarely meet. But when Nike is footing the bill, the classic hot dogs-and-a-Slip 'N Slide formula gets thrown out the window. On Thursday night, the sportswear giant hosted a gi-normous plein air fête in front of its new Mercer Street boutique. It was a block party all right…on steroids. Mark Ronson, who lives above the new store, came out of self-imposed DJ retirement to man the turntables, spinning vintage tracks while chatting up downtown types like Nate Lowman and Tom Sachs. Spike Lee and Roger Federer did the ribbon-cutting honors, with a little help from the Soul Tigers marching band. "Is Brooklyn in the house?" asked Lee. Apparently, the abundance of sullen hipsters quaffing Heinekens failed to tip him off.

There were, of course, hot dogs, courtesy of Nathan's. There was also stadium seating, jumbo screens showcasing artist-commissioned sports-themed videos, and a posse of furry mascots cavorting about. Serena Williams arrived with an entourage roughly the size of the aforementioned marching band. Apropos of her Olympic gold-medal doubles win, the tennis queen sported various gold accoutrements as well as gold toenail polish. "It was my stylist's idea, but I'll take the credit," she chuckled. Williams is in town to compete in next week's U.S. Open, but we were more interested in her Olympic Village experience. "Honestly? I felt totally fat," she confessed. "I was surrounded by people who looked freakishly perfect. I was like, 'OK, I'm not working hard enough. I've gotta go on a diet.' " Tennis stars…just like us.

— Evelyn Crowley