I can't remember which thread I saw this, and can't think of a good way to search, but I remember a video posted (at least I think it was a video) quite a while ago, many months at the least, that showed how simple rules can lead to complex scenarios, showing a computer simulation of simple objects with an input and output (I think) with simple rules, and how different combinations of these objects resulted in much more complex patterns of 'behaviour'.
I suspect it was a zumby posting, but I'm just hoping someone remembers it enough to be able to give me a link? TIA