Phelps on his way to another gold medal
In China he's known as 'the Flying Fish'; in America they call him 'the Baltimore Bullet'.
Whatever you call him, American swimmer Michael Phelps looks destined to become a household name across the world after breaking the Olympic record for most gold medals in a single Games.
Phelps's total of eight golds in Beijing put him one ahead of compatriot Mark Spitz's previous tally set in 1972.
Michael Phelps dominated the field in seven of his races and set an amazing seven world records in the process. He did, however, have one close shave in the 100m butterfly which he won by the smallest possible margin of just 0.01 seconds, and in another he had to contend with a faulty pair of goggles.
Now people are already calling him the greatest Olympian of all time. But whether he is or not, what is it that makes Michael Phelps so good?
A good place to start might be his physique. Phelps has the perfect body shape for a swimmer: his armspan is longer than his height, he has very flexible joints, huge lungs, and his incredibly large feet (size 14 in the US, size 49 in China) act like flippers in the water.
To feed his huge swimmer's body, Phelps eats an astonishing 12,000 calories a day, six times the average for a man of his age.
According to his coach, Phelps starts with a breakfast of champions: "Three fried egg sandwiches with cheese, tomatoes, fried onions and mayo, a five egg omelette, a bowl of grits, three slices of French toast and three pancakes with chocolate chips."
He then slips into a swimsuit which has been making waves in the world of swimming. Designed by NASA, the American space agency, the suit is made of a special material which is said to help athletes swim 2% faster.
Michael Phelps should spare a thought for his mum, who first pushed him into swimming as a way of making friends, and who believed in him when one teacher said he would never be a success.
Whatever the reason for his success, Phelps admits there was perhaps also a bit of luck involving in winning his eight medals.
"I guess eight is a lucky number for me, too, now. The opening ceremony started on 8/8/08. Maybe it was meant to be," he said.