Initial terrain types were placed with the help of the map at Blue Planet Biomes rivers and elevation info were found at the University of Texas' Perry-Castañeda Library Map Collection. Downloaded kswoll's map maker (CFC thread here), and used the handy-dandy image trace feature to lay out continents and oceans. I started off with a regular physical map, cropped it, ran it through the 'spherize' filter (vertical only) in Photoshop to squish the poles and enlarge the equatorial and temperate regions, then adjusted the aspect ratio so it matched that of the Earth map which shipped with Civ4 (124圆8 tiles, or about 1.82:1).