Even before a single Olympic medal has been hung around his neck, Michael Phelps is rewriting the manual on what it means to be a world-class swimmer. Entered in five individual events and a candidate for each of the three relay races in Athens, Phelps has the potential to win eight gold medals, and eclipse the standard held by Mark Spitz, who won seven golds in 1972. It's a long shot, but no one is better prepared to do it. Just 19, Phelps holds the world record in three of those five individual events and is a fingernail's distance from the record in a fourth.

In a sport in which most athletes would be happy to qualify for one event, that he can try for eight medals is amazing. Trained in the individual medley, an event that requires mastery of all four swimming strokes, Phelps possesses a phenomenal ability to compete with the best specialists in three of those strokes—butterfly, backstroke and freestyle. In the fourth, the breaststroke, he's merely outstanding. In fact, at the U.S. Olympic swimming trials last month, Phelps became the first swimmer to qualify for six individual events. (He will drop the 200 backstroke in Athens.) "He is really redefining our expectations of swimming excellence," says Pablo Morales, a two-time Olympian in the butterfly and Phelps' role model. "He is blazing his own trail now, and there is probably a whole global army of young swimmers who are looking up to him."

His talent in the pool propelled Phelps to turn pro at age 16, before graduating from high school. He is an anomaly in the swimming world, a multimillionaire with endorsements from Speedo, Argent Mortgage, Visa, Omega, AT&T Wireless and PowerBar. If he equals Spitz's haul of seven golds from a single Games, Phelps will earn an automatic $1 million bonus from Speedo.

Money isn't enough, though. Phelps wants to make swimming matter. He sees the attention that Americans lavish on their swimmers every four years evaporate between Games, and he desperately wants what Australian swimmer Ian Thorpe has—the prestige, the celebrity and, not least of all, the marketing clout to stand, here in the U.S., with the best athletes. "People don't think about swimmers when they look for athletes to sponsor," he says with some frustration. "You don't see a swimmer doing a Sprite commercial. We have so many other sports to take [people's attention] away from swimming. But if something good happens this summer, that may change."

Phelps' biggest impediment on the way to swimming history may well be his own teammates, many of them Olympic medalists and world-record holders. And then there are the Australians, with a younger and deeper men's team that would dearly love to grind the Americans into chum. They are eager to write the coda to their 4 x 100-m medley-relay defeat in Sydney, where U.S. swimmer Gary Hall Jr. had claimed that the Americans would "smash [the Australians] like guitars." The Aussies won the next two relays, on the back of Thorpe, and mockingly played air guitar in a pool-deck celebration. The first stanzas of their Greek chorus have begun; Thorpe has called Phelps' attempt at a Spitzian haul of golds "ridiculous." Phelps' response: "He's saying he doesn't think it's possible for him to do that. I don't think I would say it's impossible." If that were any frostier, they'd have to speed skate to settle it.

Although Phelps is clearly the standout star in a bright galaxy of American swimmers, some of his teammates bristle at the recognition he receives. The U.S. men's team boasts world-record holders in seven events—Phelps in the 200-m and 400-m individual medleys and the 200-m butterfly, Brendan Hansen in the 100-m and 200-m breaststrokes, Aaron Peirsol in the 200-m backstroke and Ian Crocker in the 100-m butterfly. Peirsol and Crocker have beaten Phelps to the wall this year, and Crocker famously halted Phelps' run at a perfect six golds and six world records at the 2003 world championships. "I don't think anyone holds any ill will or anything, and Michael certainly deserves the attention he is getting," says Peirsol. "But this is one of the best teams that the U.S. has sent to the Olympics, so I hope everybody on this team gets the credit they deserve." Phelps won't be racing Peirsol in the backstroke at the Olympics, but he will face Crocker in the 100 fly. "If Michael wants to [beat Spitz's record], he's going to have to do it himself," says Crocker. "I'm definitely not giving any favors."

It's the same tension that Thorpe and his teammates have been grappling with since the Australian catapulted to stardom in the run-up to Sydney. Thorpe's status has isolated him from the camaraderie of the swimming circle, and inevitable jealousies have erupted over his special status. "We have never had a Michael Phelps before," notes Rowdy Gaines, a triple gold medalist in 1984. "He can swim a lot of events, and that can create a lot of jealousy." Phelps does not sound all that bothered. "If it comes up, it comes up," he responds with typical teenage aplomb. "I'll just deal with it."

Growing up with two sisters who swam competitively, Phelps was practically raised at the pool. "The summer he was born was the summer I started swimming," says his oldest sister Hilary, 26. "The poor kid was always getting dragged to the pool." His mother Debbie remembers bringing baby Michael along in a carrier and parking him on the pool deck during his sisters' practices. When he was 7, Phelps learned to swim, but it took weeks before he could do anything more than the backstroke. "I was afraid to put my head underwater," he admits.

Once he did, his talent surfaced almost immediately. Swimming with the North Baltimore Aquatic Club at age 11, he set a national record for his age group in the 100-m butterfly. That caught the attention of Bob Bowman, then an assistant coach at the club. "What I noticed about him was that he was fiercely competitive in everything he did, whether it was swimming a race or playing a game at the pool," he says. "He always wanted to win." Bowman called Phelps' parents in for a meeting, alerting them to their son's potential, and in 1996 laid out a 15-year plan that would include Phelps' being a part of the 2004, 2008 and 2012 U.S. Olympic teams. "I'm thinking, This man is crazy," Debbie recalls. "This is my 11-year-old baby, and you're projecting 2012?"

Bowman could see that Phelps was born to swim. Blessed with a sinewy, whiplike body, a long torso and large hands and feet, plus a 6-ft. 7-in. arm span that extends 3 in. beyond his height (the usual ratio is 1 to 1), Phelps has as close to an ideal swimming body as you can get. Like other top swimmers, he doesn't so much power through the water as slide along it, propelled by a vigorous dolphin kick that surges from his head to his toes in a high-amplitude wave.

Capitalizing on that, Bowman tried Phelps in other strokes and found that the gangly teen was a quick learner with an uncanny feel for the water. Still, Phelps says, "he took every single stroke and changed it. From Day One, he wanted me to swim multiple events." That meant an early focus on the individual medley—the grueling test of all four strokes, which Phelps picked up with little argument.

The teen did balk, though, when Bowman tried to fix his starts and turns, the one area in which Phelps falters. In a sport measured in hundredths of a second, getting a smooth start can mean a world record; not wasting time at the wall can separate medal winners from also-rans. Phelps hasn't perfected his turns, says Bowman, because he is simply too good a swimmer. "He'd think, I'll just swim a little harder, and then say, 'That was a best time. How can you complain about that?'" As his swimming was taking shape, though, Phelps' family was breaking up. The same year he learned to swim, Debbie, a Baltimore County school administrator, and Frank, a Maryland state trooper, decided to divorce. The couple had built a home on a five-acre spread in Harford County, Md., more than 60 miles from the Baltimore pool where their children were training. The round-trip drives, sometimes twice a day, were wearying. Debbie wanted to move the family to Baltimore; Frank wasn't so sure. It was one more issue in a deteriorating relationship. Phelps and his sisters remained with their mother, and when Hilary and Whitney moved away for college, his bond with his mom deepened.

She's sensitive to his growing celebrity and the jealousies that can flower in his classmates and is vigilant almost to a fault. "When he went to a dance in high school, for example, I would tell him, 'Michael, please be careful. If you put your glass down, don't pick it back up'—things like that," she says, fearing everything from recreational drugs to banned substances. "It makes me sound like a nagging mother, but I always try to keep 10 steps ahead of him." Says Phelps: "We've gotten so much closer over the past few years because it's only been us. She's loosened up a bit. I guess you could say she's sort of like a chill mom." Last Christmas Phelps surprised her with a new Mercedes, and this spring he bought her diamond earrings for her birthday. Phelps is not nearly so close to his father. "I wouldn't say it's necessarily a bad relationship, but I wouldn't say it's the best relationship. And the way my life is right now, I wouldn't want anything to change."

In Bowman's grand plan, Phelps would have watched—not participated in—the 2000 Olympics, but Phelps' butterfly had progressed so quickly, the pair found themselves at the Olympic trials. By the fourth day, Phelps had earned a berth to Sydney.

The youngest member of the swimming contingent, at 15, Phelps finished fifth in the only event he raced, the 200-m butterfly, and vowed that the next time he went to the Games, he would not leave without a gold. "I was disappointed walking away from Sydney with nothing," he says. "People were saying [fifth is] good, and I was saying, 'No, it's not. I want more.' It's something that's been with me ever since."

Like most 19-year-olds, phelps has stuck on his wall, in a prominent spot right next to his bed, a picture of a fit figure in a bathing suit. But this being the ultrafocused Phelps, don't expect the latest beauty from the Sports Illustrated swimsuit issue. Instead, it's rival Ian Crocker celebrating his world record in the 100-m butterfly at the 2003 world championships—and his win over Phelps. That's the image that gets Phelps up at 6 a.m. every day and into the pool. "After losing the 100 butterfly at world's, I was even more motivated to train every day and get faster," says Phelps. "I hate to lose. I absolutely hate to lose. I can't stand it."

In a way, Phelps makes it easy for Bowman, because getting the teen to the pool to log seven miles a day, 365 days a year ("Christmas morning, I'm at the pool," notes Phelps), is never a problem. Money, malice (in the form of taunts from competitors) and missteps—"He turns anything into a reason to work harder," says Bowman. "I call him the motivation machine."

While training for the world championships last year, Phelps received an unexpected kick from Thorpe's coach, who asserted that Phelps was not in the same league as Thorpe. Bowman slipped a copy of the comment into Phelps' mailbox at the pool. His response was devastating: he broke five world records; Thorpe broke none. "It's lunacy to give Michael any ammunition whatsoever," says Olympian Gaines. "He thrives on confidence. Giving him more fuel in the way of criticism is suicidal when it comes to swimming against him."

Phelps will rely on that competitive fever, so prevalent in Sydney, for his 200-m freestyle race against the Thorpedo. He is not the favorite, and it's probably his longest shot for a gold—or even a medal—against the Aussie. The two swam against each other at the world championships in the 200 individual medley, which Phelps won by 3.62 sec. But this event would be the first head-to-head freestyle race between today's two greatest swimming talents, and Phelps welcomes the challenge. "I love to race the best, and I've never faced him in the 200 freestyle," he says of Thorpe. "It's something I've always wanted to do." When Bowman suggested scratching the event from his program in Athens, Phelps said, "Absolutely not."

It will be another first—two millionaire swimmers in a duel at the pool. Can't you just see a million-dollar, winner-take-all rematch during half time at the Super Bowl? Phelps has indeed changed swimming. So, yes, Michael—we are likely to be paying attention, well beyond the Olympics.

• ALICE PARK