Michael Phelps (Top) of the United States swims during the men's 200m butterfly semifinal at the Beijing 2008 Olympic Games in the National Aquatics Center, also known as the Water Cube in Beijing, China, Aug. 12, 2008. Phelps entered the final with 1 minute 53.70 seconds. (Xinhua/Ding Xu)

Katie Hoff (C) of the United States competes during the semifinal of women's 200m individual medley at the Beijing 2008 Olympic Games in the National Aquatics Center, also known as the Water Cube in Beijing, China, Aug. 12, 2008. Katie Hoff was qualified for the final with 2 minutes 10.90 seconds. (Xinhua/Ding Xu)