Conspiracy! CCG is the first work in production by the open source design project 4GXG (for gamers by gamers).
4GXG is a wiki where the public contributes rules, designs, story, ideas, essentially everything to game designs. You can download the initial rules (DOC), and card samples.
For added bonus, $10,000 has been allocated to contributors, with $2,500 already haven been given away.