There's a geek-funny series of cartoon videos on YouTube called, "How It Should Have Ended." Basically, the name says it all. They take popular movies (particularly those that geeks might be interested in) and give it an alternate ending. They are quick astute and pointing out absurdities in movies and rectifying the situation by providing their own hilarious conclusions. Check out the samples below.
Their website is www.howitshouldhaveended.com or you can find them all over YouTube.