Explore Alterra is a tabletop RPG that eschews a character sheet in favor of cards that measure spells, weapons, armor, talents and items. It is a very straightforward system, and an interesting setting.
Star Trek Counters
The Heavy Metal Wargaming site has some counters for use in starship games set in the Star Trek: The Next Generation universe.
Scratch Build Modular Catwalks
Here’s a video with advice on building modular catwalks. The techniques also can be used for a variety of science fiction projects.
MiG Madness – Fast Play Rules For Jets
Wargamer and Teacher Matt Fritz has written MiG Madness, a set of free wargames rules for playing air combat in the Korean War.
Middle Earth Paper Models
Games Workshop’s Lord of the Rings battlegame boxed sets come with some bits of terrain to get you started. This page has some paper buildings for Rohan and Gondor to keep you moving along.