kiva.org for micro-lending
Teacher, are you looking for an interesting way to introduce economy and the concept of "work" to your students? Try micro-lending to a person in need in another part of the world. Students can track the loan and read updates on how the loan is helping to make a difference. It's really awesome. When your $25.00 loan is repaid you can choose another person and re-invest your $25.00 again. It's a great way to integrate service learning into your Math and Social Studies curriculum.