Our Olympics Correspondent Simon Harris is tweeting from a briefing on the London 2012 Opening Ceremony.
Artistic director Danny Boyle (who directed the Oscar-winning film Slumdog Millionaire) is describing his vision for the show.
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Transport for London is not happy that its branding has been used.
If you've been anywhere near Trafalgar Square today you'll notice something different.
Look closely at this collection of images by photographer Jim Grover and you'll notice there's something missing.