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 some star ladies
One of the track highlights on Friday is the women's 1500m, won by Kelly Holmes as part of her golden double in Athens in 2004. Dame Kelly is one of three women to pull off the 800/1500m double at the Olympics, after the Russians Tatyana Kazankina in 1976 and Svetlana Masterkova in 1996. At the 1988 victory ceremony there was a mix-up with the medals, with the silver being presented to third-placed Tatyana Samolenko instead of her Russian team-mate Laimute Baikauskaite, who had finished second. They quietly swapped them afterwards.
It's a middle-distance double for the ladies, with the 5000m as well. Tirunesh Dibaba, the 10,000m champion in Athens and in London, won this event in 2008 so is going for a repeat double. The 5000m has only been contested since 1996: before that there was a 3000m race, the first of which was the infamous encounter in 1984 in which Zola Budd clashed with Mary Decker, sending the local favourite tumbling out of the Los Angeles Games.
It's also the women's hammer, with Sophie Hitchon having set a new British record to qualify for the final. Cuba's Yipsi Moreno has won silver at the last two Games, and is in the final again this time. The hammer was only added to the women's Olympic programme in 2000.
The only men's individual title at stake today is in the pole vault, an American preserve from the first modern Olympics in 1896 through to 1968 - 16 successive gold medals before Wolfgang Nordwig of East Germany upset the applecart in Munich. In 1952 and 1956 the winner was the Reverend Bob Richards, who was known as "The Vaulting Vicar" (or sometimes "The Pole Vaulting Parson"). Fittingly, two Poles have won the pole vault: Tadeusz Slusarski in 1976 and Wladislaw Kozakiewicz in 1980.
There's been much British success over the years in the men's 4x400m relay, although the plucky Brits haven't actually won gold in the event since 1936, when the quartet included Godfrey Rampling, father of actress Charlotte. The team anchored by Roger Black took silver in 1996 behind habitual winners the United States, who finished first in every final since 1956, apart from 1972 (when Kenya won) and 1980 (when the USA didn't compete). But, after no American athlete reached the final of the individual 400m for the first time ever (excluding 1980 when they were absent), will it be a different story this time?
In the Serpentine it's the turn of the men's long-distance swimmers in the 10km marathon. This was introduced at the last Games in 2008, and Welshman David Davies won silver, just behind the Dutchman Maarten van der Weijden. Davies, 27, has also won an Olympic medal in the indoor pool: he took bronze in the 1500m in Athens in 2004, in a race won by the great Australian Grant Hackett.
Both BMX cycling gold medals will be decided today. Britain's Shanaze Reade is among the favourites for the women's race, while in the men's event there's a return for Maris Strombergs, Latvia's only gold medallist from the Beijing Games.
It's finals day in the women's hockey, with Netherlands - the defending champions from Beijing - taking on Argentina for the gold medal. Before that Britain take on New Zealand in the third-place playoff in the Riverside Arena, hoping for their first Olympic medal since taking bronze in Barcelona in 1992. Women's hockey was first played at the Olympics in Moscow in 1980, when the surprise winners were Zimbabwe.
Off the Dorset coast it's the medal race in the women's 470, where Hannah Miles and Saskia Clark basically just need to finish ahead of the New Zealand yacht to take gold. It's an event in which Britain has never yet taken a medal in six previous attempts. The Australian boat, skippered by 2008 gold medallist Elise Rechichi and crewed by Belinda Stowell, who won gold in Sydney in 2000, looks certain to finish off the podium this time.
And finally, lovers of glitzy glamour will be glued to the synchronised swimming team event, won by Russia at the last three Olympics, although the United States took the first such gold, in Atlanta in 1996. The Russian teams of eight in 2004 and 2008 included Anastasia Davydova and Anastasiya Yermakova, who also won gold in the duet event