The story of the Earth's water cycle is a fascinating one, as Bill Nye demonstrates in Bill Nye the Science Guy: Water Cycle. He tells students that water they drink today may have been around during the days of the dinosaurs. Of course, it has gone through the cleansing effects of the four phases of the water cycle, which he proceeds to explain. The material can be complicated, but because Nye relates it to the kids' experiences and everyday activities, it is easier to understand. The sometimes garish graphics, the jokes, puns, and general air of silliness make it fun to pay attention.
Disney Educational - Bill Nye The Science Guy: Water Cycle