Here's a quick stop motion animated film I created in about 10 minutes using the free "Lego Superhero Moviemaker" app on the iPhone.
Of course Lego would like you to use Lego-branded products to make animations. But there's no stopping you from using anything you have lying around your desk. Say, a Chewbacca action figure or a robot dog toy, for example.
So easy and fun to use!