Where can I find volunteer opportunities around the world?

Summary:

Idealist's volunteer center offers a list of organizations to contact and Northwestern University coordinates overseas service-learning projects for the US.

In the Idealist Volunteer Center there's a catalog of organizations that support volunteering in many countries of the world: see http://www.idealist.org/volunteer/travel.html

"Just Naive Enough" is a program of Northwestern University that assists with overseas service-learning projects for American undergraduates. http://www.justnaiveenough.org/