America's Promise
Collaborative network that facilitates volunteer action for children and youth. Founded after the Presidents' Summit for America's Future in 1997.
http://www.americaspromise.org/

Do Something
Encourages young people to create their own vision for making a difference in their community and provides them with the resources and support needed.
http://www.dosomething.org/

Nicodemus Wilderness Project
Provides global volunteer opportunities that empower youth to help save the environment while they develop important leadership skills. Project essays and photos are published online as an educational resource.
http://www.wildernessproject.org

Youth Service America
Volunteer opportunities in all 50 states. Enter a zip code and find organizations in that area needing help. Provides details of membership, forthcoming events, and newsletter.
http://ysa.org/

Volunteer Canada
Connects youth with community service organizations throughout Canada and provides online volunteer resources. [English and French]
http://volunteer.ca/en/volworks