I was playing with the crater shader and came to the conclusion that you can have negative values for craters
. This means you can turn craters into spikes. Playing around with the crater shader I created the olympic logo.. sortof. There's just a basic power fractal applied to the planet, the rest is crater shader. For some reason the back spike is cut short. Don't know why that happened, should be as tall as the one on the left. The 3D view showed it allright.
Here's an another attempt at combining craters (both positive and negative values).
This one also has a strata and shear shader applied.
I know these aren't the best of renders, they're just intended to show the crater shader at work. It can produce some interesting effects, maybe it'll inspire someone to do some more interesting stuff with it
Sorry if this is all known stuff, but I didn't see it mentioned yet I think.