How do I Animate a Ball on a flexi membrane

I want to roll a ball around a plane and have the plane flex out of the way, leaving an impression in the plane wherever the ball rolls. How do I set it up so the ball deforms the plane as it moves?

I think the best way to do this would be use an animated texture set to affect the displacement of the plane. A very good example of this can be found at:
Scroll down and look for ‘’.