Serious Fun

IT WAS EARLY EVENING when they came rushing out the door of Credit Suisse First Boston's New York City headquarters and into the June heat, young men and women in groups of four, corporate dress shed for more casual togs, running shoes double-knotted. Sporting cell phones, digital cameras, street maps, and clue sheets, they were all geared up for the Urban Challenge. Part trivia contest, part scavenger hunt, part road race, the game guides participants through a dozen clues as they race from