I made a Geonosis diorama, I tell ya!
I can't get pics up at the moment, but I basically cut all of the structures from this styrofoam-like stuff that you get at craft stores (It's green, comes in blocks, and you're supposed to stick fake flowers in it.) I made the spire from two of those blocks, then glued those halves together. It is not very tall, but I like it. I glued down all of the other land features, then covered it with metal screening, like the kind you'd use to put outside your windows to keep bugs out. The spire did not get the screen treatment. I then covered everything in paper machette(sp.) and after it dried, I painted it a rust color. All this was done two years ago with a friend, so I'm probably leaving out some things.
Hope that helps, and I'll try to post pictures of it some day. Some day.