I hope this isn't too OT -- here's a good profile in Fortune Magazine's online site about Xtranormal, the company that allows us to make those animated movies (Allegheny Jet's about the N+1 factor is the best, but I couldn't find a link to it in a quick search).
The company was founded as a way for people in movie production to do quick storyboards....but got re-purposed as a way for amateurs to do quick online movies when the first business plan didn't work. (You may have also seen that these have gotten popular enough that Geico has used one in one of their insurance ads).
Here's the profile of the company and its background:
Here's a sample movie, in case you haven't seen one before: