Four-time Olympic champion Michael Johnson previews the 2012 Olympics, which promises to be one of sport's great events. Usain Bolt, Michael Phelps and Ben Ainslie, who boast multiple gold medals and are aiming for more in London, give their insight into what makes the Olympics so special. There is also an interview with one of the potential stars of this year's Games, Great Britain's teenage diving world champion Tom Daley.
And with 100 days to go until the Games start,…