DonorsChoose.org - Teachers Ask. You Choose. Students Learn.
DonorsChoose.org is a non-profit organization that works with people from all over the web, to enrich and enhance the opportunities of students all over the US.
According to the site:
DonorsChoose.org is a simple way to provide students in need with resources that our public schools often lack. At this not-for-profit web site, teachers submit project proposals for materials or experiences their students need for more effective learning. These ideas become classroom reality when concerned individuals, whom we call Citizen Philanthropists, choose projects to fund.
On completion of a project, donors receive a feedback package of student photos and thank-you notes, and a teacher impact letter.