http://www.freecycle.org/

The Freecycle Network (often abbreviated TFN or just known as Freecycle) is a non-profit organization registered in the state of Arizona, USA, and separately registered as a UK charity,[1] that organizes a worldwide network of "gifting" groups, aiming to divert reusable goods from landfill. It provides a worldwide online registry, and coordinates the creation of local groups and forums for individuals and non-profits to offer and receive free items for reuse or recycling, promoting gift economics as a motivating cultural outlook. "Changing the world one gift at a time" is The Freecycle Network's official tagline.