The Michael Phelps-endorsed body suit is only one of the high-tech inventions at this year's Olympic Games, the San Francisco Chronicle reports. NASA-designed shoes, 3D motion-capture-designed bicycles, and a Nike PreCool vest have all garnered attention. But the most controversial is a spring-enhanced shoe that track and field athletes will wear this week.
The Spira Stinger sports a spring in its midsole—a direct violation of Olympic rules. But company owner Andy Krafsur has called the rule outdated and challenged it. Oversized tennis rackets and metal golf drivers "were banned once, too," Krafsur said. "Now that's all you see. Rules can never keep pace with technological change." (Read more sports technology stories.)