Genet Models offers some free paper models for Dropships, Shuttlecraft, a Science Fiction Tank that looks like it is from the movie Aliens, and some science fiction style warehouses.
science fiction
The Last Human RPG
In this unusual free role playing game, you play a simple robot charged with defending the last human being. The Last Human is written by Nathan Russel as a part of the 24 Hour RPG Challenge.
Post-Apocalypse Armored and Armed Winnebago
Squirmydad has a paper model of a post-apocalypse armed and armored Winnebago.
One Page Fleets Starship Combat
One Page Fleet is Mike Wikan’s set of free wargames rules for starship combat.
Iron Stars demo rules
Majestic 12 Games has these demo rules for their Iron Stars miniatures wargame. I’ll let them explain:
Iron Stars is a game of space combat in an age of steam and steel. Set in a fictional universe based loosely on the writings of H. G. Wells and other fantasists, it provides a back story and ship designs from an alternate history in which the Martian Invasion actually happened, the ether is all?pervasive, and Cavorite is a reality. But, as with Starmada and other Majestic Twelve Games products, the focus is on players’ imaginations; a clear and concise ship construction system is provided so you can pit your own space dreadnoughts against the likes of the Royal Navy Ether Squadron or the German Aethermarine.