Where the crowds are banging on the windows to the Museum of London, the writing on the glass is the word "Welcome" in many different languages.
(at around 4 mins) When Gary Shoefield first steps outside his flat in Hackney this is #17 Beck Rd, Hackney, London. It still has the same color door, visible in Google Streetview.
At 46m 43s Ray Santilli and Gary Shoefield both have cameo appearances in the center of the frame for a few seconds. They are seen in the crowd very close to Ant and Dec as they leave the theatre.
Dean Lennox Kelly and Clive Swift were cast in major cameos but replaced before filming.
Stephen Marcus in two scene role as a thug is among six performers whose roles ended being deleted in post.