I enjoy watching time lapse stuff too. People, plants, places, whatever its always pretty cool. I have no photography experience at all (disclaimer) but a shot every 5 seconds would be an insane about of photos. Not just to store, but to work with later. Although it would look way smoother, like a video, but I think every 5 seconds would be overkill. There's got to be some info out there on the interwebs somewhere. Or hell, if you've got a camera capable just experiment and see for yourself. It might take a while if your plan was to sit back and wait for the info to come to you.
Also, while I'm writing this I see there are a few 'similar threads' at the bottom of the page here. Should probly check em out.
