There were cheers too as the crowd saw a film featuring an unlikely meeting between the Queen and agent 007 James Bond.
"Good evening Mr Bond," the Queen said in the clip, before they left together, apparently heading towards the Olympic Stadium in a helicopter.
The aircraft then flew over the stadium to the sound of the Bond theme tune, as two figures parachuted down, one dressed as the monarch.
As if by magic, the Queen appeared in the stands - part of a crowd of about 80,000 - amid cheers.
Mr Bond was not the only much-loved British character to take part. Mr Bean prompted laughter when he appeared as part of the orchestra playing the Chariots of Fire theme.
The ceremony also celebrated the National Health Service by featuring a cast of more than 1,000 volunteers recruited from hospitals across the country, including Great Ormond Street children's hospital in London.
All the action was played out to a soundtrack of some of Britain's most iconic bands - including the Clash, the Rolling Stones, Queen, the Sex Pistols and David Bowie - with Sir Paul McCartney performing live at the show's close.
The athletes taking part in the Games - led by Greece, the Olympics' spiritual home - made laps of the stadium bearing their nations' flags.
And Bradley Wiggins, wearing a yellow jersey, rang the world's largest harmonically-tuned bell to launch the opening ceremony.
As the 'Isles of Wonder' show began, artistic director Danny Boyle pledged a ceremony with a theme of "this is for everyone".
The Oscar-winning film director later tweeted: "Thank you, everyone, for your kind words! Means the world to me."
Earlier, crowds of people, many of them dressed in their nation's colours, streamed into the Olympic Park for the show.