This guy enspired me http://sponeil.org. Yes it is a planet render, I've had some good results from the perlin noise generator for my Alert fighter project http://www.cerebral-bicycle.co.uk/viewdoc.asp?doc=319.

The planet here has been generated at run time from a single random seed. The problem is that it's a fixed size sphere, which doesn't get an more detailed as you get closer. I have a LOD sphere written to support the merge and split based on a Diamond Algorithm published at http://www.binstar.com but I've hit a snag on actually when to perform the merge or split. :?