Whereas in the past, time measurement was carried out by hand, today's electronic chronometers are extremely accurate and have always been a peaceful judge at the Olympic games. Indeed, the most renowned manufacturers fight to be associated with the Olympic movement. At the Sydney 2000 Games, the Swiss Swatch group - the official timekeeper of the Olympics - issued marathon runners, cyclists and triathletes with microchips which allowed their position to be determined to within a second. Transmitters weighing just five grams fitted into runners' shoelaces and cyclists' race numbers relayed information to electronic display boards.At the same time, yachtsmen were issued with a black box and GPS satellite navigation system with which their position could be calculated to the nearest metre.Finally, the cameras traditionally used for photo finishes were replaced by digital devices that enabled high-quality images to be viewed on giant screens, on television and the Internet.The stop-watches are generally accurate and reliable. However it has been known for them to fail. This happened at the 1992 Barcelona games during the 100 m freestyle final. An electronic fault led Stephane Caron to believe he had won the silver medal. In fact he had to settle for the bronze.Another incident occurred at the Munich games when the Swedish swimmer Larsson and the American McKee touched the side of the pool at the same time after the 400 m medley. Larsson was declared the winner, but only after the judges had had to measure the swimmers' times to a thousandth of a second, where usually a hundredth of a second is sufficient.