Community Rights Counsel (CRC)

http://www.communityrights.org

A nonprofit, public interest law firm that provides strategic assistance to state and local government attorneys in defending against takings claims. Includes monthly "Community Rights Report" newsletter.

Defenders of Property Rights (DPR)

http://www.yourpropertyrights.org

Conservative property rights movement center that litigates, lobbies, and engages in public relations on the takings issue.

Environmental Law Institute's Endangered Environmental Laws Program

http://www.endangeredlaws.org

Progressive research institute that defends and reinforces the constitutional foundations of environmental law by providing education, information, and assistance to those in the legal, policy, business, and advocacy communities. Includes recent cases that have applied the "new federalist" or other controversial legal theories to environmental law.

Georgetown Environmental Law and Policy Institute (GELPI)

http://www.law.georgetown.edu/gelpi

Progressive research institute focused on environmental issues, especially takings. Includes surveys of case law and state and federal legislation, as well as monthly "Takings Snapshots"

http://www.law.georgetown.edu/gelpi/takings/courts/snap.htm

PropertyProf Blog

http://lawprofessors.typepad.com/property/

Part of the Law Professor Blogs Network, a source of recent developments in property law.

Public Employees for Environmental Responsibility (PEER)

http://www.peer.org

National nonprofit alliance of public employees dedicated to upholding environmental laws and government accountability. Includes news, white papers, and employee surveys.