Protect the Constitution

Keeping church and government separate as in the Constitution
Americans United for Separation of Church and State

Protect your right to a day in court
Center for Justice and Democracy

Try to keep science responsible
Center for Science in the Public Interest
(Be sure to get their poster of dangerous chemicals in foods)

Read the CIA and MI5 documents you're not supposed to see
Cryptome

Speaking the truth
Project Censored

Keeping Wal-Mart and McDonald's in their place
Sprawl Busters

For whistleblowers
Government Accountability Project

Help end deficit spending to fund the world's biggest defense budget
Act Blue