The adventure archives is a collection of RPG adventures. Currently, they're mostly for GURPS, with some D&D 4th and Hackmaster thrown in, but they're all very easily converted to whatever rules system you're using.

These adventures are free, though if you use them, I'd love to hear how they went! E-mail me!

Sci-Fi Adventures

Traveller Adventures is a collection of two GURPS adventures set in the universe of Traveller, though they can easily work in any far future setting. It includes an encounter with a strange human experiment in "Noble Fugitive" and a twice kidnapped princess in "Twin Ransoms." Available in full-color .pdf (373k).