Congratulations to Avri Klemer for Martian 12s, the winner of the Winter 2008 Icehouse Game Design Competition. It is a gambling game for two to five players, and like all the entries in this materials-restricted competition, it requires two (and only two) Treehouse sets to play.
A round of applause from The Gameshelf for all twelve eight games entered into the contest! All are listed on the competition page, with links to each game's rules.
D'oh, you stole my thunder, I was going to post about it. I guess I still can. (By the way, there were only eight games entered.)
Bah, can't count. Fixed!