Nikon has released a nifty flash application called Universcale. From their website:
“We are able to view all entities, from the microworld to the universe, from a single perspective. By setting them up against a scale, we are able to compare and understand things which cannot be physically compared.
Today, using the electron microscope and astronomical telescope, we can see the objects which we have not been aware of its existence before. Are you able to fathom, or even roughly grasp, these sizes?”