A pendulum clock in the science center in Valencia, Spain. The balls are knocked down every 15 minutes, and I happened to catch one being ticked off ;) In the reflection of the pendulum you can see a small hole where the balls drop into once they are knocked off their stand.

Levels, sharpening and resize done on PS. No cropping.

Grabbed from my pbase site so the exif didn't come through unfortunately. If you wish to see it, here's the link: http://www.pbase.com/image/21754626