Freecycle

The Freecycle is a non-profit organization that organizes a network of gifting groups aimed at diverting reusable goods from landfills.

Freecycle is a grassroots and entirely nonprofit movement of people who are giving (and getting) stuff for free in their own towns and neighborhoods. It's all about reuse and keeping good stuff out of landfills. Each local group is moderated by local volunteers (them's good people). Membership is free.