Amazing swivelly sculpture thing, made by John Edmark. Spin it one way and it makes a nice neat shell/leaf-like shape, spin it the other and it falls into the Fibonnaci configuration that plants use to maximise sunlight hitting their leaves. He also does lots of other Fibonnaci-based sculptures: He has quite a lot of other inventions – some of which are of tangential practicality… There are quite a lot more amazing kinetic sculptures on his site. Brilliant.