I used to frequent a website with nearly a hundred experiments like this, almost all interactive and very beautiful. They were all created with Flash/ActionScript. There were lots of tree visualizations, fluid simulations, and one specific demo with randomized bugs that walked around using inverse kinematics. I've since lost the link, does anyone remember what I'm talking about, maybe could provide a link?

[Edit] found it http://levitated.net/daily/index.html http://levitated.net/daily/levWalkingThings.html