Don't let out any opening ceremony secrets: Boyle

Tens of thousands of spectators attended a technical rehearsal on Monday, one of the final run-throughs before Friday's £27 million ($42 million, 34.5 million euro) spectacular.

The Olympic Stadium in London. Pic/Getty Images

The ceremony's artistic director, film-maker Danny Boyle, pleaded with the audience - which included guests of the Games organisers and families of those taking part - not to leak out details about the event, which is set to be watched by billions worldwide on television.

The Twitter hashtag "savethesurprise" was emblazoned on the stadium's giant screens. Boyle, 55, who directed the hit films Trainspotting and Slumdog Millionaire, and his creative team have done their best to keep most details of the opening ceremony secret.

But the Oscar winner acknowledges that in the age of social media and camera phones, keeping everything under wraps will be impossible. - u00a0