Some tens of thousands more are lucky enough to have a seat inside the Olympic Stadium, the centerpiece of the Olympic Park in east London.
Dubbed Isles of Wonder, it promises to be quite a show -- but then it needs to be.
The opening ceremony, attended not only by thousands of athletes but also Queen Elizabeth II and more than 100 visiting heads of state and foreign dignitaries, sets the scene for the Games to come.
Torchbearers Jennifer Saunders and Joanna Lumley, known for their "Absolutely Fabulous" characters Edina and Patsy, carry the Olympic flame through Lambeth, Kensington and Chelsea on Thursday, July 26 in London. The flame is traveling 2,875 kilometers (1,786 miles) through the United Kingdom over 70 days. Its journey ends Friday at the opening ceremony of the London 2012 Olympic Games.
Torchbearer Ifeyinwa Egesi holds the Olympic flame inside the Globe Theatre in London on Thursday.
Torchbearer Rhyania Blackett-codrington, right, passes on the Olympic flame to comedian David Walliams, left, before setting off from Islington Town Hall July 26.
The Olympic torch is carried Thursday on top of an open top bus down Oxford Street in London.
Indian Bollywood actor Amitabh Bachchan, center, carries the Olympic flame through the streets of London on Thursday, July 26, the day before the opening ceremony.
Wheelchair basketball player Adedoyin Adepitan of Great Britain carries the Olympic flame Thursday over Millennium Bridge in front of St. Paul's Cathedral in London.
Torchbearer Paris Walker holds the Olympic flame Thursday as it travels on a barge at Camden Lock in London.
Torchbearer Daniel Mccubbin holds the Olympic flame inside St. Pancras International Railway Station on Thursday, July 26.
Torchbearer Scott Moorhouse, a Paralympic javelin thrower, runs with the Olympic flame along Tottenham High Road in London on Wednesday, July 25.
Spectators watch as the flame makes its way up Tottenham High Road on Wednesday, July 25.
James Cracknell carries the Olympic flame on the torch relay leg through Kingston Upon Thames on Tuesday, July 24. The flame is traveling 2,875 kilometers (1,786 miles) through the United Kingdom over 70 days. Its journey ends Friday at the opening ceremony of the London 2012 Olympic Games.
Explorer Amelia Hempleman-Adams carries the Olympic torch as she stands on the roof of a pod on the London Eye in central London on Sunday, July 22.
A spectator sits atop a phone booth as people gather to watch the Olympic torch pass through Greenwich in London on Saturday, July 21.
Torchbearers "kiss" their torches to pass the Olympic flame during the London 2012 torch relay through the Borough of Tower Hamlets in London on Saturday, July 21.
British Royal Marine Martyn Williams abseils from a helicopter with the Olympic flame into the grounds of the Tower of London on day 63 of the 70-day relay, which has involved 8,000 torchbearers.
British sailor Sir Robin Knox-Johnston runs around the restored Cutty Sark ship with the London 2012 Olympic Torch in Greenwich, south London, on Saturday July 21.
David Boyle carries the flame on a boat rowed by the Maidstone Rowing Club during his leg through Maidstone, England, on July 20.
Christopher Bury carries the flame through Mote Park in Maidstone, England, on July 20.
British artist Tracey Emin holds the Olympic flame inside the Turner Contemporary Gallery in Margate alongside "The Kiss" sculpture by Rodin on Thursday, July 19.
Torchbearer Daisy Shepherd of East Sussex carries the Olympic flame through Hastings on the southern coast of England on Wednesday, July 18.
Torchbearer Kathy Gore of Uckfield runs with the Olympic flame at Seaford Head in front of the Seven Sisters cliffs in East Sussex on Tuesday, July 17.
Keith Leech of Hastings uses the Olympic flame to light the cauldron in Hastings on Tuesday, July 17.
Thomas Mules carries the Olympic flame on Pulpit Rock, Portland Bill, on Friday, July 13.
Relay fans watch Andrew Clutton from the top of a ship's mast as he carries the Olympic flame between Hamworthy and Poole on Friday, July 13.
Ryan Hope carries the torch Thursday, July 12, on the row boat Penny off the waters of Weymouth.
Schoolgirls outside Salisbury Cathedral on Thursday hold the torch carried by retired sprinter and four-time gold medal winner Michael Johnson.
Olympic gold medalist and former sprinter Michael Johnson carries the flame at Stonehenge onThursday.
Prince Philip, Queen Elizabeth II and Lord Sebastian Coe watch as Olympic torchbearer Gina Macgregor passes the flame to Phil Wells at Windsor Castle in Windsor, England, on July 10.
Competitive canoeist Zachary Franklin carries the flame at the Lee Valley White Water Centre in Waltham Cross, England, on July 7.
Lauren Reeder, a teaching assistant, is surrounded by local children while carrying the torch in King's Lynn, England, on July 4.
Retired police officer Glenn Chambers carries the flame through heavy rain in Lincoln, England, on June 28.
Torchbearer Eugene Perry carries the Olympic flame at Sutton Bank in the North Yorkshire Moors National Park in York, England, on June 20.
Joseph Forrester, 12, and children from Madras College run along West Sands in St. Andrews, Scotland, on June 13.
Andrea Strachan, a competitive swimmer, carries the Olympic flame along the shore in Lerwick, Scotland, on June 10.
Actor James McAvoy carries the torch down Buchanan Street in Glasgow, Scotland, on June 8.
Triathlete Peter Jack holds the Olympic flame while on the Giant's Causeway in Northern Ireland on June 4.
Comedian John Bishop carries the Olympic flame on top of the Jodrell Bank Observatory in Jodrell Bank, England, on May 31.
Television presenter, adventurer and writer Ben Fogle carries the Olympic flame in a hot air balloon on May 19, the first day of the relay.
And the organizers of the London Games are well aware they have a tough act to follow after the Beijing extravaganza four years ago, which featured thousands of drummers, acrobats, martial artists and dancers performing under a light display at the soaring "Bird's Nest" Stadium.
So what can those watching the ceremony this time around expect to see?
Some details have been released already, but many more remain a closely guarded secret.
Keeping a secret this big isn't easy, though, when there are thousands of performers and technicians involved, not to mention the audiences for two dress rehearsals this week.
A Twitter hashtag, #savethesurprise, started by Olympic organizers to appeal to those in the know not to spoil the show for others, has been embraced by many, although not all.
Giant screens also displayed the message within the stadium during the rehearsals. Those who opted not to play along have incurred the social-media wrath of many who do want to "save the surprise."
What the organizers have revealed already is that the show, masterminded by artistic director Danny Boyle, best known for the Oscar-winning film "Slumdog Millionare," draws its inspiration from Shakespeare's "The Tempest."
It will begin this Friday night with the tolling of the largest harmonically tuned bell in Europe, cast by the nearby Whitechapel Foundry.
The show's opening scene -- dubbed "Green and Pleasant," after a line from poet William Blake's Jerusalem -- will then unfurl, presenting an idyllic view of the British countryside.
The elaborate set will comprise rolling hills, fields and rivers, complete with picnicking families, sport being played on a village green and real farmyard animals.
These will include ducks, geese, 12 horses, three cows, 70 sheep and three sheepdogs to keep them in line.
The national flower of each of the four nations that make up the United Kingdom will also be represented -- the rose of England, the Scottish thistle, Welsh daffodil and flax from Northern Ireland -- organizers say.
In case the heavens don't open for real, Boyle has lined up fake clouds to shade his pastoral scene.
It's expected that three more set-pieces will follow, including a special sequence celebrating the "best of British," featuring volunteer performers from the NHS, or National Health Service.
Then will follow the traditional elements of the ceremony, as required under the International Olympic Committee charter, the organizers say.
The Queen will be greeted at the entrance to the stadium by IOC president Jacques Rogge.
Then the athletes -- who, after all, are the real stars of the Olympic show -- enter the stadium, team by team in alphabetical order, apart from Greece, which enters first in recognition of its status as the birthplace of the Games, and Great Britain as the host nation, which enters last.
Each team delegation will be led in the parade by a visiting head of state or dignitary -- in the case of Team USA, by Michelle Obama, who has said the honor "is truly a dream come true."
After speeches from Olympic officials -- including Sebastian Coe, head of the London organizing committee and himself a former gold medallist, the Queen will declare the Games open and the Olympic flag will be hoisted above the Stadium, to fly throughout the event.
A participating athlete, judge and coach from Britain will then take an oath vowing to compete and judge according to the rules of their respective sport, one hand holding the flag and the other held aloft.
The grand finale will see the Olympic torch enter the stadium, the last stage in a 70-day relay around the United Kingdom, and set the Olympic cauldron aflame, symbolizing the beginning of the Games.
Who the final torchbearer will be has been the subject of much speculation.
One name mentioned has been that of footballer David Beckham, although he told CNN Tuesday that the honor should go to someone who has competed at the Games. Others speculate that a group of athletes could be involved.
Whoever it turns out to be will have the eyes of the world upon them as they wrap up a spectacle that, in the words of Boyle, aims to "be as unpredictable and inventive as the British people."