Alley Cat Allies
The most comprehensive resource for everything TNR.
www.alleycat.org

Feral Cat Project
First free-standing clinic formed for free-roaming cats. Located in Washington State. Great site with a clinic model resource.
www.feralcatproject.org

Chicagoland Stray Cat Coalition
Local Chicago resource that provides trapping assistance and more to area caretakers.
www.chicagolandstrays.org

Neighborhood Cats
based in NYC, they divided the development of one of the most comprehensive community-wide TNR programs today. They work both locally and nationally and their site is a great resource.
www.neighborhoodcats.org