On BBC3 at the moment is a series called "Movie Mistakes".
Amongst the mistakes it shows are scenes were continuity is all over the place.
This can include people wearing different clothes in the same scene, so when you cut back and forth between people talking the person can be seen wearing different clothes.
Or if a scene is over a meal, and the people are eating the drinking, then as the scene goes on the same glass can be full, then empty, then full, then half empty and so on.
Some of these scenes are quite funny, like in say a car crash when say the front winscreen is shattered, then a few seconds later in the same car, the windscreen is back normal again