Many more good ones here: EDF, Centronia, etc.

Refugee Division Intern - Internship
Posted by: Human Rights Watch - Washington, DC
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/BwxbCj2GDCxd/

US Legislative/Foreign Policy Internship - Internship
Posted by: Human Rights Watch - Washington, DC
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/mGX24G3w96W4/

Family Literacy Program (FLP) Intern- Fall 2011 - Internship
Posted by: CENTRONIA
Location: Washington, District of Columbia, United States
Salary: Transportation stipends available for metro and bus rides
http://www.idealist.org/view/internship/354S42kP5Bk5P/

Environmental Defense Action Fund Research Intern - Internship
Posted by: Environmental Defense Fund
Location: Washington, District of Columbia, United States
Salary: Competitive hourly rate
http://www.idealist.org/view/internship/GzsMdnf8hZ5P/

Special Events Coordinator - Internship
Posted by: Friends of Compass
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/WwC4gfzX832D/

Resource Development Internship - Internship
Posted by: Partners of the Americas
Location: Washington, District of Columbia, United States
Salary: Stipend TBD
http://www.idealist.org/view/internship/f3Tf2mD27SP/

Federal Regulatory Policy Internship - Internship
Posted by: OMB Watch
Location: Washington, District of Columbia, United States
Salary: $12-17 hour
http://www.idealist.org/view/internship/KhbpwJZ3Xh8d/

Neighborhood Development Intern - Internship
Posted by: U.S. Green Building Council
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/m6b8x8wK2H8d/

Education Intern: Fall 2011 - Internship
Posted by: Association of Reproductive Health Professionals (ARHP)
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/xZZcKxSHFgnp/

Program Intern - Internship
Posted by: Break the Cycle
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/wt66wJGC3C2D/

Policy Intern - Internship
Posted by: Break the Cycle
Location: Washington, District of Columbia, United States
http://www.idealist.org/view/internship/H8Wg9ZtKZJjd/