Got lots from Matrix:Reloaded! When Neo is taken by the agents for interrogation in the first movie, we can see a shot of him in the interrogation room from an array of television sets, which zoom in. That's the same array of television sets from the Architect's room.
One night on the 2 mile stretch of highway made for the movie, a security guard decided to race his car up and down when no one was around. He did, but he totalled his car and instead of telling anyone, he just ran off and was never seen again. (A little bit of info from Keanu Reeves on an interview on the Tonight Show).
The 'twin' characters are non-film actors, but carpenters by trade, whose only other screened work was on UK TV programme Carol Vorderman's Better Homes (DIY show). They have done some stunt work, but got the part when the makers of the film were looking for identical male twins who were both skilled in martial arts. 🙂