Devex - http://www.devex.com/
A global organization with jobs, business opportunities, professional networking, and news for professionals working in international development, global health, and foreign assistance.
Overseas Jobs - http://www.overseasjobs.com/
Provides a list of international job opportunities searchable by career field.
The world's leading on-line gateway to information on humanitarian emergencies and natural disasters.
UN Jobs Vacancies - http://unjobs.org/organizations
A great web site for students seeking International Employment Opportunities with the United Nations.