It is a quintessential Olympic moment, hundreds of athletes marching into the stadium, drenching the field in the banners and colors of their nations. But when the 2004 Summer Games in Athens begin with this traditional opening ceremony, take a closer look.
That sprinter wearing a British uniform? He was born and raised outside Sacramento and had never been to Britain until last month.
The familiar-looking woman with Slovenia? She competed in the six previous Summer Games, winning numerous medals, as a Jamaican.
And what about the Greek baseball team? All but two of the players grew up in the United States or Canada.
The Athens Games will include dozens of men and women who have taken advantage of a little-known rule, swapping nations to compete under a different flag.
Some have fled poverty, looking for a new home with better coaches and facilities. Others have returned to the land where a parent or grandparent was born, where they face less competition to make the national Olympic team.
Sports officials call the number of athletes crossing borders a growing problem. Even more worrisome are cases in which athletes appear to be motivated by profit.
Several world-class Kenyan runners have recently moved to the oil-rich emirates of Qatar and Bahrain, where governments hungry for athletic talent pay them handsomely. This has prompted an angry response from the International Olympic Committee.
"From a moral standpoint, we should avoid this transfer market in athletes," IOC President Jacques Rogge told reporters. "What we don't like is athletes being lured by large incentives by other countries and giving them a passport when they arrive at the airport."
A Bahraini sports official, who confirmed that his nation's army pays salaries and expenses for two Kenyans, wondered about all the fuss.
"They don't have a chance to survive in Kenya," Shuber Alwedai, general secretary of Bahrain's athletic association, said in a telephone interview. "How do they live? How do they pay rent?"
The trend of athletes on the move has grown common enough that the international track and field federation -- which has seen more than 100 "transfers of allegiance" in the last four years -- has established a working group to consider new rules.
The issue could prove tricky to resolve, however, because each Olympic sport is governed by separate national and international federations with a mishmash of policies.
The Olympic charter, hovering above them all, has its own set of regulations.
Olympic rules state that an athlete "must be a national" of the country he or she represents. For anyone looking to switch, that entails acquiring citizenship. In many cases, such as the U.S. ballplayers, athletes can do so while remaining citizens of their native lands.
Next comes a waiting period. Newcomers may not represent their adopted country in the Olympics until three years after they last competed for their former country in any major competition.
Jamaican track legend Merlene Ottey followed this lengthy procedure. Telling the international track federation that she preferred Slovenia's calm lifestyle, she moved to the city of Ljubljana in 1998 and eventually became a citizen. She is now eligible to represent that country in Athens.
But not everyone waits.
Many nations are quick to give incoming athletes a passport, even in this post-Sept. 11 world.
Last month, U.S. runner Malachi Davis -- a California native whose mother was born in London -- received a passport from Britain and, arriving in that country for the first time, was awarded a spot on the Olympic team.
Davis had found a way in: Because the former UCLA athlete never represented the U.S. in any major meet, he was starting with a blank slate, IOC officials said. The same was true for the North American players on the Greek baseball team.
Other athletes have avoided the three-year period by persuading their former country to help them petition for early eligibility. Israel let sprinter Attila Farkas switch to Hungary last year.
The change did not go as smoothly for Stephen Cherono, a Kenyan steeplechase runner who changed his name to Saif Saaeed Shaheen and moved to Qatar, where, international track officials said, the government agreed to pay him $1,000 a month for life.
The Kenyans initially consented to the transfer, in part because the Qataris pledged to finance construction of a stadium in Cherono's hometown of Eldoret.
But Kenya has since grown worried about the so-called "brawn drain," with as many as half a dozen of its top athletes leaving.
"Of course it is of great concern," said Isaiah Kiplagat, chairman of the nation's athletic federation. "If we allow that, we are going to destroy our athletic society."