Exactly two years until the most prodigious sporting event on the planet is launched in the UK capital and the buzz is already huge.
Sporting stars, including four-time gold medallist Sir Chris Hoy, eagerly made their way to the Olympic Stadium on Tuesday to participate in the London 2012 countdown.
Sir Chris became the first person to test out the velodrome, which he helped design, and ex-sprinter Michael Johnson (pictured) raced against young athletes on a specially-laid track.
Retired basketball player John Amaechi shot the first hoop in the basketball arena.
Mayor Boris Johnson and Lord Sebastian Coe, London 2012 chairman, were also at the Olympic Park in Stratford, East London, where they launched the next phase of preparation - the campaign to find 70,000 people to volunteer at the Games.
Sir Chris made no secret of his exhilaration: "I had goosebumps on my arm. To me now the Games are coming alive."
He added: "You can really sense it is getting more enthusiastic - two years to go, I really cannot wait."
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