While I was diggin around for old Pyjamazon files I came across some test animation I did. It's nothing spectacular - just something thrown together.
I love to do this after I've designed a cast of characters - and it's a great exercise. It's fun, quick, cheap and you'll learn tons about the limitation of your characters.
I usually grab some BG off the web (this one originally had baloo and mowgli in the middle of it - gotta love PS) then I find some old audio clips that match the characters (in this case Alf and Buzz Lightyear). Some fun music or sound FX then I throw some simple animation on top of it all.
I find it super gratifying to see my characters come to life.