One Saturday night in October, one of my rare weekends in New York (Emily and Eli were visiting their cousins in Madison, Wisconsin), Julie and I had gone to a party at Sharon Rivkin's apartment on the Upper East side. Sharon is a close friend and an old colleague from my NBC days. A fortysomething Manhattan native and urban warrior, she is currently a producer for Dateline and chronically single, but with an assorted coterie of friends in the art and media worlds. About a hundred people were packed into her one-bedroom apartment on East 83rd Street between First and York Avenues, and by the end of the evening everybody was more or less drunk