It appears that in the new "Transformers" movie (which simply kicks all kinds of ass) there is a continuity error concerning Air Force One. Granted the movie is about extra-terrestrial mechanical transforming aliens - but putting that aside for a moment - Air Force One changes aircraft types during the film.
In the establishing shot of Air Force One in flight, it is the normal 747 that we're used to seeing whenever it is portrayed on screen:
Photo © Weimeng
We then see several sequences inside the plane before it is forced to land. Upon landing it it surrounded by police, FBI, NTSB etc. In that shot, it has changed (transformed?) into the classic Kennedy / Johnson era 707 Air Force One:
Photo © Marc Lehmann
The engines are a dead giveaway. You can only see from mid-wing to the tail onscreen but it is definately a 707. Just thought it deserved a mention. Look for it if you go see the movie.
BTW, I HIGHLY recommend it. The special effects are astounding, excellent story and it's funny too.