MICHAEL SILVER, a senior writer at Sports Illustrated, is a highly respected sportswriter and coauthor of several bestselling sports memoirs. He lives in Northern California. NATALIE COUGHLIN has built a reputation as the most versatile, dominant swimmer in the world. Seizing five medals at the 2004 Olympic Games in Athens--two gold, two silver, and one bronze--Natalie's performance is considered the best in Olympic history by any American woman.