Andy Murray: tennis
Britain's Andy Murray, the world number-four men's tennis player, is determined to perform better in front of his home crowd at next month's London Olympics than he managed in Beijing four years ago.
Murray, 25, beaten in the first round in 2008, says: 'It was one of the best experiences of my life being part of the Olympics. But I was very disappointed with the way I played. Winning a medal this summer is one of my major goals.'
This week he is competing at the Wimbledon Championships, the world's most prestigious grand-slam tournament, which started on Monday. He will return to Wimbledon's All England Club to play in the Olympic competition, along with Novak Djokovic, Rafael Nadal and Roger Federer.
World number-two Nadal, 26, the defending Olympic singles champion, will carry Spain's flag at the July 27 opening ceremony; the tennis starts the next day.
'[It's] the most important competition in the world of sport,' he says. 'For everybody - all the sports, all the people in sport - competing in the Olympics is probably the most special thing.'
Federer, 30, of Switzerland, the world number three, won gold in the men's doubles with compatriot Stanislas Wawrinka in Beijing. But the six-time Wimbledon singles champion wants to emulate Nadal and win the 'golden grand slam' - all four grand-slam singles titles and the Olympic singles title.
'With the history I have at Wimbledon, it's going to be super exciting,' says Federer, who is likely to carry his nation's flag at the opening ceremony, too.
World number-one Djokovic, of Serbia, the reigning Wimbledon champion, won bronze in the singles in Beijing.
In the women's event, Russia's Maria Sharapova, who will carry her nation's flag at the opening ceremony, has her eyes on the golden grand slam, too, after claiming the fourth slam at this month's French Open.
Sharapova, 25, will achieve a big ambition playing Olympic tennis this summer. 'It's been a dream since I was very young; I'm thrilled it's at Wimbledon. It's my favourite place to play tennis.'
Russian women won all three singles medal in Beijing: Elena Dementieva, gold; Dinara Safina, silver; and Vera Zvonareva, bronze.
In London, 86 men and 86 women, picked from the world rankings, will play in five events, including 16 seeded players in each of the singles. A nation can enter up to six men and six women.
Tennis was an Olympic sport at the first modern Games in 1896. Wimbledon hosted Olympic tennis at the 1908 London Games, when Britain - top of the all-time medals table with 16 golds - won all six gold medals. But the sport was dropped from the Olympics after the 1924 Paris Games and did not return until the 1988 Seoul Games.
Fab Fact: John Boland won the singles and doubles for Britain and Ireland after entering while on holiday during the 1896 Athens Games