So about a week ago I discovered Phun, a 2D physics sandbox. It's an awesome toy. You should check it out. Anyway, I made one of those ball clocks. It was a lot more work than I thought it would be, but at least it's done and I can stop obsessing about it. (Well, it does get stuck occasionally so maybe I can't. And I wonder if I could do the same thing with water. How about a thing that builds a wall and knocks it over? So many possibilities...)
I just put up a video on YouTube (after spending a really long time figuring out how to encode one the right way). You however, are lucky, and can see a good quality version of this video. You might need to install VLC to play it though. If you already have Phun installed, you can also download the .phn file. Just unzip and drop it in your Scenes folder.