You've probably seen time lapse movies of clouds moving through the sky, or flowers opening. Maybe people walking in the street, boats crossing the bay, or snails eating ivy.
I'm already using my 256 MB R-Pi as a video game play time for my boys. Now it's time to move on!
My interest in time-lapse comes from my dad, who built many mechanical devices to slice time into long segments, turn on and off growing lights, picture taking lights, and carefully controlled 16mm movie cameras which had not been designed for single frames.
I've already researched the web-cams which work with a Pi and it seems quite a few of the Logitech models are OK.
Combine this with camstream and/or ffmpeg, one can take a series of images and then combine them into a movie file.
After that, configure a web server on the Pi, and enable Bonjour device discovery, along with a wireless dongle. Now anyone can easily connect to the Raspberry Pi's web page, where there will be buttons and images showing how many frames have been taken since the last time a movie was created. You can push a button to create a new movie, and then watch the result. Of course you will also be able to control the interval at which images are captured.