a great place to start is with
WiserEarth.
it's the world's largest database of citizen groups working for change in environmental issues, social justice, and rights of indigenous people (all connected of course).
paul hawken started it -- he's the founder of smith & hawken, and author/co-author of
the ecology of commerce,
natural capitalism, and most recently,
blessed unrest, which i just finished this morning. blessed unrest's subtitle is "how the largest movement in the world came into being, and why no one saw it coming."
excellent stuff to get you fired up!!!