I've put together a project called the "Map Mosaic"
Basicaly, there is one Half Life 2 Death Match map split into 10 areas. There will be one mapper per area, each of these mappers will create what ever they want in their "area" of the map.
Anyone is welcomed to join, you can read more about the project on the website.
http://docglass.net/Game_Mosaic.htm
btw, there is no limit of space on the project, once ten 'areas' have been taken spots will be doubled up and the first person to finish will have there section put into the first map, then a second map will be started, and so on and on and on.