Federal Jobs Central - www.fedjobs.com

USA Jobs  - www.usajobs.opm.gov

Foreign Policy Association - www.fpa.org/jobs_contact2423/jobs_contact.htm
Lists employment opportunities for people interested in foreign affairs and international relations.

FedWorld - http://www.fedworld.gov
Lists federal government positions.

U.S. Department of Labor - www.dol.gov

Jobs in Government - www.jobsingovernment.com

Federal Jobs.net - www.federaljobs.net

USA Jobs.gov - www.usajobs.opm.gov
Federal job openings nationwide.

United Nations - www.un.org

Think Tanks

Centers for Research & Policy Development Centers for Research & Policy Development (international) http://www.ksg.harvard.edu/library/orgs_tanks.htm

Think Tanks and Public Interest Organizations (national) http://usinfo.state.gov/usa/infousa/politics/thnktank.htm