Cracked.com has a very cool article pointing out some neat hidden easter eggs and other cool stuff hidden in films!
Hidden images in posters? Pixar teasing their future film projects in their current movies? People speaking in foreign languages in a movie are spoiling the entire plot for you but you don't realize it? Is there actually a plot to McBain's films from the Simpsons? What is hidden in the music of Inception?
Check out the link here to learn some interesting stuff!