Back to props! I needed to rig a couple of props, so I have used a script I wrote a while ago to use a dynamic rotation pivot. The setup is fairly simple though. It's a Locator that acts as a rotation pivot and slides over a curve while trying to get as close as possible to another locator that is in the center of the object, and moves a little in the direction of the rotation.
It is simpler than it may sounds and I never get tired of the result!