Washington, August 25 : Golden boy Michael Phelps was greeted by an estimated 40,000 people as he marked Beijing's handover of the Summer Games in the next host city, London.
The crowd had gathered in front of Buckingham Palace for the Visa London 2012 party after the Beijing Olympics came to an end.
While on stage, the swimmer who won a record-breaking eight gold medals in Beijing talked about his joyful experience during the games.
"It was the perfect week, the perfect races - couldn't ask for anything else," People magazine quoted him as saying.
Along with Phelps' appearance, there took place free concerts throughout the day.
The London crowd also watched the closing ceremony for the Beijing Olympics during which David Beckham, Jimmy Page and Leona Lewis contributed to the handover segment.
The Red Arrows team of nine jets performed a fly-by overhead, leaving trails of red, white and blue smoke above Buckingham Palace, before Phelps left the stage.
"Too cool. I've never seen something like that before," he said.
As regards what the Games might be like in 2012, Phelps said: "Hard to imagine, but this is a great start. It's going to be amazing. I'm kind of at a loss for words because I was like, 'Oh, you know, I wonder how many people are going to be there.' I'm staring down this street of people just packed together. It's one of the coolest things I've ever experienced."