1. NATURE

General environmental
Earth First! Journal
Black Rhinocerous

All Species Foundation
Biotic Baking Brigade
Bush Green Watch
Center for Biological Diversity
Center for Science in the Public Interest
Climate Change Portal
Climate, Community and Biodiversity Alliance
Climate Hotmap
Conservation International
Crop Choice
Earth Action
Earth Economics
Earth Island Institute
Earth Policy Institute
Eco-Action
Eco Portal
Ecoterrorists
Environmental Defense
Environmental Investigation Agency
Environmental Investigation Agency Ecocrimes Campaign
Environmental Research Foundation
Fauna and Flora International
Forest Conservation Portal
Forest Service Employees for Environmental Ethics
For Mother Earth
Free the Planet
Friends of the Earth - US
Friends of the Earth International
Global Justice Ecology Project
Global Reponse
Golf Kills
Green Action
Green Anarchy
Greenpeace
Millennium Ecosystem Assessment
National Audubon Society
Natural Resources Defense Council
Rising Tide
Save our plants
Scorecard - pollution information site
Society for Ecological Restoration
Sierra Club
Student Environmental Action Coalition
Watertalk
Wildlife Conservation Society
World Commission on Dams
World Conservation Monitoring Centre
World Conservation Union
World Resources Institute
World’s Water
Worldwatch Institute
World Wildlife Fund - US
WWF's Global Network
WWF International

Habitat specific - North America
Alaska Acton Center
Allegheny Defense Project
American Lands Alliance
Campaign for Old Growth
Conservation Northwest
Dogwood Alliance
Earth Roots
Ebbets Pass Forest Watch
Ecology Center - SF Bay Area
Endangered Species Coalition
Forest Action Network
Forest Guardians
Forests Forever
Forests of the Congo
Headwaters Forest
Heartwood
National Forest Protection Alliance
Native Forest Council
Native Forest Network
Oregon Natural Resources Council
Raincoast Conservation Society
Save the Peaks
Washington Wilderness Coalition
Western Lands Project
Wild Earth
Wilderness Committee
Wilderness Society
Wild Rockies
Wild Wilderness

Habitat specific - Rest of World
Action for Community & Ecology in the Regions of Central America
Amazon Watch
COAMA - Programme for the Consolidation of the Amazon Region
Friends of the River Narmada (India)
Global Witness
Goongerah Environment Centre
International Rivers Network
Landless Workers Movement (Brazil)
Network of Indian Environment Professionals
Otway Ranges Environment Network
Rainforest Action Network
Rainforestweb
Rivers Watch East and Southeast Asia
Sierra Madre Alliance
South East Asia Rivers Network
Stop the Fortis Dam (Belize)
Taiga Rescue Network
Western Australia Forest Alliance
World Rainforest Movement (Uruguay)

Species specific (general wildlife, then alpha by species group)
African Wildlife Foundation
Born Free Foundation
Care for the Wild
Defenders of Wildlife
International Wildlife Coalition
Wild Aid
Wildlife Search
World Animal Net
World Society for the Protection of Animals

Birds
Barn Owl Centre
Hawk and Owl Trust
New Zealand Penguins
Peregrine Fund
World Owl Trust
World Twitch

Bison
Buffalo Field Campaign

Elephants and rhinos
Amboseli Ttrust for Elephants
Elephant Information Repository
International Rhino Foundation
Save the Elephants
SOS-Rhino

Marine life
American Cetacean Society
America's Whale Alliance
Coastal Alliance for Aquaculture Reform
Industrial Shrimp Action Netork
International Whaling Commission
Living Oceans Society
National Coalition for Marine Conservation
Ocean Defense International
ReefGuardian International
Reef Net
Reef Relief
Sea Shepherd
Sea Web
Watershed Watch Salmon Society
Whale and Dolphin Conservation Society
Whale Shark Research Group
Wild Salmon

Predators
Carnivore Conservation
Cat Specialist Group
Felidae
Predator Conservation Alliance

Primates
Borneo Orangutan Survival Foundation
International Primate Protection League

Turtles
Sea Turtle Restoration Project
Sea Turtle Survival League

Animal rights
Ameican Anti-Vivisection Society
American Humane Association
Animal Concerns
Animal League Defense Fund
Animal Protection for New Mexico
ASPCA
Eastern Shore Chicken Sanctuary
Friends of Animals
Fund For Animals
In Defense of Animals
International Fund for Animal Welfare
McSpotlight
No Compromise
People for the Ethical Treatment of Animals
Physician's Committee for Responsible Medicine
Progressive Animal Welfare Society
Rocky Mountain Animal Defense
Society and Animals Forum
Stop Huntingdon Animal Cruelty

Vegan and vegeterian resources
EarthSave International
International Vegetarian Union
Vegan Outreach
Vegan Society
Vegan Straight Edge
Vegeterian Resource Group
Veg Web

Population control
Center for Research on Population and Security
International Planned Parenthood Federation
Negative Population Growth
Population Action International
Population Connection
Voluntary Human Extinction Movement