Apparently, the US version is Dennis Quaid pitching ideas for films to a studio executive, and as he pitches each idea, we get to see it played out.
The UK version is two stoner kids who try to play a joke on the brother of one of them by telling him about a "banned" movie called "Movie 43", and while he's searching for it online, he finds a number of different films it could be and we see those.
Quite a marked difference I suppose - wonder why they did that?
Hmm, the US one sounds better to me.
Very strange to have a totally different way to frame a movie in different countries. it's bad enough when we get renamed versions and shoddy DVD extras over here!