In addition to the links below is a list of companies which provide industry internships.
General
About.com
Campus Career Center
Center for International Career Development
College Grad Job Hunter
Embassy & Diplomatic Scholars Internship Program
Experience.com
InternJobs
Institute for Experiential Learning
Community and Economic Development
Institute of Cultural Affairs
International Economic Development Council
Redefining Progress
Consulting Firms
Deloitte Consulting
Ernst & Young
Public Strategies
Environment/Energy
Environmental Protection Agency
ExxonMobil
National Parks Conservation Association
National Wildlife Federation
Nature Conservancy
Natural Resources Defense Council
Resources for the Future
Sierra Club
Student Conservation Association
Texas Commission on Environmental Quality
Federal/State
Ag and Natural Resources Policy Congressional Intern Program
International Development
Asian Development Bank
Foundation for International Community Assistance (FINCA)
Institute of Development Studies
World Trade Organization
World Bank
Study Abroad
The Embassy Site
Transitions Abroad
United Nations
International Policy
Center for International Policy
Council on Foreign Relations
Delegation of the European Commission to the United States
U. S. Department of State
Research Institutions
Abt Associations, Inc.
Heritage Foundation
Institute for Policy Studies