My first experiment was to stitch together a bunch of stills I had taken a couple of years ago of a hummingbird in my camera's high-speed mode. That worked reasonably well, but the originals weren't very clear, so neither was the resulting clip (which only runs a couple of seconds).
Then I figured I'd try just setting up a camera on a tripod, and using an intervalometer to take a frame every 30 seconds. That worked pretty well, so I added some titles and a soundtrack. Here's the shrunk/compressed version (475kB):
Then it snowed, so I decided to try filming the snow melting, at 60 seconds/frame. The snow wasn't melting very fast, but there are some good sun shadows (235kB):
All well and good, but how about actually filming something, instead of just pointing the camera out a window? I decided to film Sammy the cat napping, and again edited in SFX (443kB):