Not a lot of people know about this website so let me take a second to explain it.  When they make movies they usually take about a week to shoot a scene.  Well, over that seven days sometime some of the props move or even change colors when the final shot is complete.  It's an accident but it would cost too much to go back and fix it.  Well, there is a website that points these mistakes out.  It's www.moviemistakes.com . You can go on there, find mistakes in one of your favorite movies and then look for them when you watch it again.  Or if you notice a mistake in a movie that isn't on there, you can submit it.  It's all free and fun.  Just something to do if you're bored and you like watching movies.

(I added mistakes I found in Wild Things, Chaplin, Driving Miss Daisy, and Scarface)