[SPOILER WARNING: This post talks about the end of "The Avengers" as well as a few other well-known movies of years past. Read at your own peril.]

When the end credits start to roll after big budget summer movies and most audience members get up to leave, sit a while and you'll notice that a select group of moviegoers stay glued to their seats.

Now, it may be that these people just enjoyed the movie so much that they want to see the names of everyone responsible. But most of the time – as with "The Avengers," which has now grossed enough worldwide to be the fourth-biggest movie of all time – it's because there's still a little bit of movie left.

More and more, those post-credit scenes are aimed directly at the geeks in the audience. FULL POST