A local New Jersey watershed protection organization sponsors this regional GIS clearinghouse. They've got lots of good content from over the years, most of it focused on the Northeast and environmental data collection/visualization.
Brief article about an intensive participatory GIS workshop held with rural Indonesians, including training of geographic and GIS concepts and fieldwork mapping, with a focus on peaceful resolution of boundary disputes between tribes and villages.
"This map illustrates (the very impossible, but intellectually exciting) scenario of the Earth standing still. If the Earth stopped spinning, the only remaining force that could affect our oceans is gravity. "
The Youth Media Reporter wrote a pretty good article and embedded some maps made by community group in Chicago. Check it out: one is environmental justice in Little Village, and another of Chicago Youth Voices Against Violence.