The Arcadia Project is calling itself the very first fully community-funded and community-assisted PC game ever attempted to be built from the ground up!
A company called Stormcloud Creations will build Arcadia: Guild of Heroes (aka The Arcadia Project), which will enable pre-order users to play actual builds of the game and suggest ideas as its being created.
The project is in the beginning stages now, with several builds already having been released.
The game itself is a management game with a role-playing game sensibility. You can recruit heroes, view detailed stats on their abilities, age, birthday, height and weight.
Build a party of adventurers and send them on dangerous quests in search of riches. Characters age, mature over time and retire.
More info for the game related aspects of the project and pre-order links are available at: http://www.stormcloudcreations.com/arcproject.htm
Entrance into the project is $19.95, and this gives any user a full version of the game when released and full access to the private forums during the complete development cycle.