Margret Snow is the quintessential New York woman.? She dresses the windows of Saks Fifth Avenue by day and mingles in the downtown art world by night, always searching for her niche in a city intent on capturing The Next Big Thing as it flies into view.? Married to Charles, a professor at Columbia, and living on the Upper West Side, the backdrop to Margret's life is made up of the poetic rhythms and colors of the Manhattan day: slow-running buses,...