There was a program on giveawayoftheday.com a few months back. It took a screenshot every x minutes then you could play it back a slideshow.
Can't find anything but I'll keep looking.
Edit: There's a program called Wink..
Smart Capture Tools: Capture screenshots automatically as you use your PC, based on mouse and keyboard input (great time saver and generates professional captures).
Works like a charm. Just set how many frames you want to take a minute (for example 2 frames a minute).