D&D: Living Greyhawk

The largest shared-world Dungeons Campaign.

Join globe-spanning adventurers as they battle despotic wizards in an unnatural desert, work against the resurgence of Orcish slavers, and thwart the plots of Vecna, Iuz and plenty of other evil masterminds. Or focus your attentions on a local region mapped onto your real-world position along with your compatriots.

More details on the Living Greyhawk homepage and on the Wizards of the Coast RPGA discussion boards.