PrecastStairs.com

Fargoth World Building Project
Features some nice maps, graphics and political information with original races, monsters, and flora and fauna. A generic gaming world for all systems. A mailing list is available for would-be collaborators.
www.fargoth.com/

The World
This is a collaborative environment for role-playing games. Players may design their own cultures, races, or religions and track how these interact with others' creations.
www.geocities.com/

Caeldera
The world of caeldera is being developed online by a group of volunteers.
www.flatearth.com/

The Santharian Dream - The Legacy to Tolkien's Fantasy
Always wanted to develop a complete fantasy world in the style of J.R.R. Tolkien? Santharian excerpts, poems, maps - you're welcome in our realm!
www.santharia.com/

ARWZ World
Alternative Reality Writer's Zone; Detailed fantasy and science-fiction worlds are created entirely by members. Anyone may join and add to the collaborative efforts in world creation.
www.geocities.com/

The World of Conclave
Draws from Oriental, African, Polynesian and other non-Western influences. Contains a beginner's guide, character journals, glossary of people, places, and things, and forums.
splendour.freeservers.com/

Unified Citizens of Earth
Finally end world government intervention through The Proclomation. Bring your persona. Now it's time to reinvent government and do it right.
gcwood.tripod.com/

Qaiyore
Qaiyore is a continent in the world of Celandra: the Unyielding Land, a game world based on the Fudgified Interactive History (FIH) system. Players take the roles of societies, rather than playing individual characters. Emphasis is placed on developing a detailed history and cultures for Qaiyore, along with myths and legends.
members.tripod.com/

Building a Redwood Canoe - Strippers Guide
Details photographs, instructions, tips and troubleshooting for constructing a redwood canoe. Also includes related links.
wooden_canoe.tripod.com/

Celandra - the Unyielding Land
A world in which 4 PBEMs occur simultaneously, in each the players play the role of societies, rather than single characters, and the purpose of the game is to plot the way of those societies through time, as well as to develop them and the campaign world further.
www.hut.fi/