Note: I've preserved my old hand-doodled version here for nostalgia's sake, but please click here for a much improved version I hashed together more recently. Enjoy!
While working on a Star Trek RPG project for Last Unicorn Games, I sketched out this quick 20-sided globe map for my own use, and it occurred to me that other GMs might have some use for a printable version of this old standby. Science Fiction games have used this projection for mapping for a long time (the version in the MegaTraveller World Builder's Handbook, by Digest Group, was my favorite, but the one in GURPS Space was also very nice, albeit a bit small, to make room for the rest of the planet data sheet). My version lacks the traditional hexagonal overlay - I just needed to make a quick conversion from the oval projection that Last Unicorn uses to this "equal area" projection to help figure out some travel times and whatnot. It's nothing fancy, but you may still find it useful.
Some helpful numbers: The (mappable) surface area of a planet is equal to approximately (Diameter x 1.5708) squared, times 4. Each triangle on the map represents 1/20th the surface area of the planet, so a planet with a diameter of 7,900 miles (Earthish size) would have a surface area of about 616 million square miles, and each triangle would represent 30.8 million of them. When placing your continents, remember that the middle triangles represent the tropics (near the equator) and the subtropics, while the outer "broken" triangles represent the range from temperate to arctic. The United States, for comparison, sits roughly between the 25th and 50th parallels in the northern hemisphere.
Just click on the image to get a printable-from-your-browser version. For an utterly excellent example of this projection applied to real planets, Calvin Hamilton's page.