List of worldbuilding resources

List any useful sites you find here.
 * http://www.elfwood.com/farp/thewriting/liljenbergworlds/ - A guide to writing realistic fantasy settings, but the science behind it makes it good for science.
 * http://www.gamingsteve.com/blab/index.php?topic=10357.30 - A list of links to guides and ideas for worldbuilding