Many moons ago I discovered that you can write on bananas with ball point pens.  It is oddly relaxing - the pen glides over the skin of the banana in a smooth fluid motion without the friction you get from paper. Go on, try it. Buy a banana and write your name on it. Write your girlfriend a poem on it. Draw a picture of a cow on it. Write your favourite verse of the bible on it (do bananas appear in the bible?)

Or do what I did and challenge a bunch of teenagers to write as many Physics Equations on a banana as possible. I think the highest we got to was 23 distinct equations (v=d/t is the same as d = vt, not two separate equations).

So here it is, our bunch of Physics Equations:

A bunch of Physics Equations