London - It's the burning question of the London Olympics.
Who will, or who should, light the cauldron for the 2012 Games?
With six months to go until the opening ceremony, British bookmakers are taking floods of bets on the issue, while fans, athletes, media and the public at large are speculating on who will get the honor.
Five-time rowing gold medalist Steve Redgrave is the big favourite with the bookies, with British Olympians Kelly Holmes, Daley Thompson and Tom Daley also in the mix. Football icon David Beckham, 4-minute miler Roger Bannister, middle-distance great Sebastian Coe and even Queen Elizabeth II are among others being mentioned.
The identity of the final torchbearer is always meant to be a closely guarded secret, so the uncertainty will go on right up until the flame is ignited on the evening of July 27.
Picture the scene:
The 80 000-seat Olympic Stadium is packed for the ceremony masterminded by Danny Boyle, Oscar-winning director of "Slumdog Millionaire." Billions of people around the world are watching on television. Various musicians, singers and dancers have entertained the crowd.
Thousands of athletes from more than 200 countries have marched into the stadium and taken their assigned places. Queen Elizabeth II has declared the games open. The Olympic anthem has been played and the Olympic flag raised.
The Olympic torch, which has been taken by boat down the River Thames to the Olympic Park, is carried into the stadium by the last group of relay runners.
The suspense and tension mounts.
Finally, someone - who? - takes the torch and lights the cauldron that will burn for the next 17 days.
In a tradition that started with the 1936 Berlin Olympics, the transfer of the flame to the cauldron symbolizes the start of the games and often stands out as the defining moment of the opening ceremony.
"Depending on how they set it up and who it is in the end, it can be great," senior International Olympic Committee member Dick Pound of Canada said. "For London, it should be somebody who in his or her own way defines Britain and sporting traditions."
The flame will arrive in Britain from Greece on May 19, heralding the start of a 70-day, 12 900km relay around the UK that will culminate with the ceremony in London.
Coe, chairperson of the 2012 organising committee, said no decisions have yet been made about the lighting.
"It will be decided by, almost certainly our creative teams, and there'll be discussions but we're not anywhere near," he said on Thursday. "I can tell you we haven't even begun to get to that granularity of detail."
Some lightings are more memorable than others.
"It's always a dramatic moment and yet most people don't remember who lit the cauldron in 2008," Olympic historian David Wallechinsky said. "They may remember Muhammad Ali, but often it's of minor significance in the long run."
As London approaches, it's worth a look back at some of the cauldron-lighting moments of previous games.
- Who can forget Ali, trembling from Parkinson's, holding the torch aloft in his right hand for several breathtaking seconds before lighting the flame for the 1996 Atlanta Games?
- Paralympic archer Antonio Rebollo fired a flaming arrow high into the night sky to ignite the flame at the 1992 Barcelona Olympics.
- Cathy Freeman - a powerful symbol of Australia's Aboriginal people - did the honours at the 2000 Sydney Olympics. Eleven nights later, she won the 400m, the only person to light the cauldron and win a gold medal at the same games.
- Members of the 1980 "Miracle on Ice" US Olympic ice hockey team lit the flame together at the 2002 Winter Games in Salt Lake City.
- Another Olympic great, nine-time long-distance running gold medalist Paavo Nurmi of Finland, lit one of the two cauldrons in Helsinki in 1952.
Symbolism has also been an important element over the years.
In 1976, two teenagers, a boy and a girl, representing English- and French-speaking Canada, were chosen to light the flame for the Montreal Games.
The final torchbearer at the 1964 Tokyo Olympics was Yoshinori Sakai, who was born on the day the atom bomb was dropped on his native Hiroshima in 1945.
The first woman to light the flame? Sprinter Norma Enriqueta Basilio de Sotelo at the 1968 Mexico City Olympics.
The youngest? Francois Cyril Grange, who was 7, when he joined French football great Michel Platini to ignite the cauldron at the 1992 Winter Games in Albertville.
More recently, Chinese gymnast Li Ning "ran" around the top portion of the stadium while suspended by wires before lighting the flame in Beijing four years ago.
At the 2010 Vancouver Winter Games, two separate lightings were held -one at the indoor opening ceremony and a second outdoors. Wayne Gretzky, Steve Nash, Nancy Greene and Catriona Le May Doan were torchbearers.
And when the Olympics were held in London in 1948?
While many had expected that miler Sydney Wooderson or even the young Prince Phillip would be the final torchbearer, it was a little-known 22-year-old medical student named John Mark who carried the flame.
"He was chosen to represent youth and vitality because of his good looks and had practiced for weeks running with his right arm held vertical," said Janie Hampton, author of "The Austerity Olympics - When the Games Came to London in 1948."
Now, 64 years later, Redgrave is the overwhelming betting favourite - 1/2 with Ladbrokes and 8/13 with William Hill.
Britain's most decorated Olympian, Redgrave won gold medals at five consecutive games from 1984 to 2000 and was knighted by the queen in 2001.
"It's hard to argue with Redgrave. He has been odds-on from day one," Ladbrokes spokesperson Jessica Bridge said.
Though he's a household name in Britain, Redgrave may not resonate with an international audience. He's also a low-key personality who is not known as Mr. Charisma.
"I don't think most Americans ever heard of him," Wallechinsky said.
Second favourite with the bookies is Holmes, winner of the 800 and 1 500m at the 2004 Athens Olympics. She's 7/1 with Ladbrokes and 5/1 with William Hill.
Teenage diver - and leading medal hope - Daley is also at 7/1 with Ladbrokes, followed by four-time cycling gold medalist Chris Hoy, former decathlon champion Thompson and Coe. Beckham and the queen are at 25/1.
Thompson, who won the decathlon at the 1980 and 1984 Olympics, is a colorful and sometimes irreverent figure. Coe gave him a plug last year, telling the Daily Telegraph: "I genuinely believe he is the greatest Olympian we have delivered."
Coe downplays his own chances.
"I've made it very clear I have massive duties around the times of the games," he said on Thursday.
A strong case could be made for Bannister, the first man to break the 4-minute barrier for the mile. Bannister ran in the 1952 Helsinki Olympics, finishing a disappointing fourth in the 1 500m. Two years later, he ran the magic time that still stands as one of the greatest sporting achievements of the 20th century. Bannister turns 83 in March.
"If there's some real icon in British sport, if it were Roger Bannister or someone like that, it could be spectacular," Pound said.
Some or all of the top contenders could be involved in the final legs of the torch relay.
There could also be a surprise flame-lighter: Perhaps a young athlete from one of the poor boroughs surrounding the Olympic Park, representing the hopes of a generation.
Hampton, the author, has a more glamorous choice - Kate Middleton, the wife of Prince William.
"My prediction for the 2012 Games is that the final torchbearer will be the Duchess of Cambridge, wearing a slinky see-through lace frock," she said. "She is popular, beautiful and can presumably run once round a stadium with one arm in the air."