All eyes are on Britain's first gold medal hope Mark Cavendish today after the spectacular opening ceremony at the Olympic Stadium in Stratford.
The 27-year-old world champion is a hot favourite for the men's cycling road race which started and finishes later in the Mall in central London.
In all 19 different sports are being staged today, with gold medals awarded in Archery, Shooting, Fencing, Judo, Swimming and Weightlifting, as well as Road Cycling.
On a sour note, Albanian weightlifter Hysen Pulaku has become the first athlete caught doping at London 2012 after failing a test for a banned steroid.
Pulaku tested positive for stanozolol in London on July 23, the International Olympic Committee (IOC) said. Two Turkish weightlifters have also been kicked out of the Games after failing pre-competition tests.
The opening ceremony, which has attracted rave reviews, was watched on TV by 26.9 million people in the UK, according to the BBC.
By comparison, peak viewing figures of 23.2 million were recorded for England's Euro 2012 quarter-final against Italy, while 17.1 million watched the Wimbledon final between Andy Murray and Roger Federer.
One of the highlights of the ceremony was the Queen making her film acting debut alongside James Bond star Daniel Craig and apparently skydiving into the arena from a helicopter.
A Buckingham Palace spokeswoman said today she was "very happy" to have taken part and was "delighted to be asked to be involved in something so exceptional".
Devised by Oscar-winning film director Danny Boyle, the £27m extravaganza started with a giant bell being rung by Tour de France hero Bradley Wiggins.
It ended with the Queen declaring the 30th Games open and seven young athletes lighting the truly breathtaking Olympic cauldron, which was made up of more than 200 flames.
In between the stadium audience of 62,000, who included heads of government and VIPs from around the world, were treated to a series of dazzling performances by the thousands of volunteers and professionals recruited by Boyle.
Among the other highlights was Rowan Atkinson creating havoc as his Mr Bean character while Sir Simon Rattle conducted a performance of Chariots of Fire.
Footballer David Beckham steered the boat which ferried the Olympic Torch from City Hall to Stratford, where it was collected and taken to the Olympic Stadium by rowing legend Sir Steve Redgrave.
In the parade of competing nations Team GB were led by Sir Chris Hoy, who won three track cycling golds at the Beijing Olympics.
The lighting of the cauldron was followed by a fireworks display and Sir Paul McCartney performing the Beatles' classic Hey Jude.
