Each day of the Games we will bring ten facts you may or may not know about the great sporting spectacle that is the Olympics. Today we have amazing feats in the pool
Today in the pool it's the final of the women's 100m freestyle, the event won three times running - in 1956, 1960 and 1964 - by the great Australian Dawn Fraser. After her third gold, Fraser's celebrations included stealing a flag from the Emperor's palace in Tokyo. She was arrested, and later banned for ten years by the Australian swimming authorities - although, since she was going to retire anyway, that didn't bother her too much.
The other women's swimming final tonight is the 200m breaststroke, in which the first champion - back in 1924 in Paris - was Lucy Morton, a Blackpool schoolteacher. The 1996 winner was Penny Heyns, South Africa's first gold medallist since their readmission to the Olympic movement. Heyns is also rather surprisingly the only woman so far to win both the 100m and 200m breaststroke at the same Games.
Michael Phelps shoots for medal No. 20 tonight in the 200m individual medley, an event he won in both Athens and Beijing. Ryan Lochte finished second in 2004 and third in 2008, and he's the defending champion in the other event being decided tonight, the 200m backstroke. In Beijing he pipped the favourite, Aaron Peirsol, denying him a repeat of the 100/200m backstroke double he'd pulled off in Athens in 2004.
The 470 yachts are in action today off the Dorset coast. The name refers to the length of the boats - they're 4.70 metres long. It's the only current class (apart from the sailboards) with separate events for men and women. Britain's men have won silver at three of the last four Games - in the hands of Nick Rogers and Joe Glanfield at Athens and Beijing - but have never won.
At Wimbledon, the tennis is reaching the sharp end: today's schedule includes the men's and women's singles quarter-finals, which in 1988 (when tennis was reintroduced into the Games) and 1992 would have guaranteed the winners a medal - but since 1996 there has been an agonising playoff for the losing semi-finalists. At Sydney in 2000, this meant that a promising youngster, Roger Federer, missed out after losing the bronze-medal match to Arnaud di Pasquale of France.
The men's table tennis champion will be crowned tonight at the ExCeL arena. China have won three of the six golds since the sport entered the Games in 1988, although there was an all-European final in Barcelona in 1992, when Sweden's Jan-Ove Waldner beat Jean Gatien of France. Waldner, who won six world championship gold medals too, almost caused an upset in Sydney when, rising 35, he reached the final but lost out to China's Kong Linghui.
At Greenwich Arena it's the final of the women's all-around gymnastics, an event won by some of the sport's greats over the years. Larisa Latynina - just deposed by Michael Phelps as the Olympian with the most medals - won the title in 1956 and 1960, but the next two golds went to the graceful Czech Vera Caslavska. The 1972 champion, Ludmilla Tourischeva, married another Olympic gold medallist, the Russian sprinter Valeriy Borzov. The outgoing champion, Beijing winner Nastia Liukin, won her gold for the United States, although she was born in Moscow.
The track cycling, scene of perhaps Britain's greatest triumphs in Beijing, starts today. Gold medals will be decided in both the men's and women's team sprints: the men's event provided one of Chris Hoy's three golds in Beijing, when he teamed up with Jason Kenny and 35-year-old Jamie Staff to see off the French challenge. GB's bronze-medal team in 1928 included three brothers - Harry, Lew and Percy Wyld - along with Frank Southall.
The women's individual archery gold will be decided today at Lord's. Britain's only medal since archery was reintroduced to the Games in 1972 was Alison Williamson's bronze in Athens in 2004, although back in London in 1908 Sybil "Queenie" Newall did take the gold, aged 53. South Koreans won six Games running from 1984, before Zhang Juanjuan of China spoiled that run at home in Beijing.
At Eton Dorney the four scheduled finals include the women's eights, an event only introduced in 1976 and won three times since by both East Germany and Romania. All three Romanian teams included Elisabeta Lipa, one of the only Olympic rowers to out-Redgrave Sir Steve - her medal haul amounts to eight (five gold, two silvers and a bronze).