I spotted one in The French Lieutenant's Woman.It is when they are on the steps on the rock jetty thing,Jeremy Iron's coat button keeps changing from being buttoned to unbuttoned and back again.
One of the biggest I ever saw was in the opening titles of "Robin Hood prince of theives". One of the actors is named "Michael" something, but it comes up on screen in big letters as "Micheal".
It's just a personal thing really, cos I am a michael and I hate it when people mis spell it. I can't believe no-one spotted this though.
My fave, also in Star Wars, in when Luke Skywalker lands his ship after the battle scenes, and shouts to Princess Leia, except he shouts "Carrie!" instead, the actress's real name, instead of her character name.
Another Star Wars one ... when all the little ships are attacking & defending the Death Star ... 2 Tie fighters cross paths, and at that exact frame, nothing's there ... they disappear, and reappear a frame later.
The CGI guys still had a lot to learn back in the 70's
in the hitcher, the young guy (not the baddie) is slammed down hard onto the bonnet of a car by a cop - and it is so forceful, his leg flings up and actually kicks the other cop in the back of the head!!
they just ignore it but what bendy legs he must have!
another one is in the movie Troy with Brad Pitt. One of the cameras is on the ground looking up at Brad Pitt and you can clearly see an airplane in the sky in the background. Dont think they exsisted around the time of the Roman Empire!!