The cartoon laws of physics as described here are rather nice. Now I feel comfortable in explaining to my daughter why the RoadRunner can pass through a solid wall painted to resemble a tunnel entrance, but his pursuer can't.
This animated sequence travels from 10 million light-years outside our own galaxy down to looking at individual quarks inside of a proton - a journey of 39 steps in factors of 10. It really gives you a graphic idea of the sheer immensity of the universe that exists outside of our common experience.