The Freecycle Network is made up of 5,000-plus groups with 7 million members across the globe. It's a grassroots movement for people to give and receive free goods locally to keep things out of landfills. Members can post things that they need or that they have, from clothes to furniture to building supplies and anything else in between. Visit here.
Note: Some of the bigger groups are hosted on Yahoo Groups, so you'll have to have a Yahoo ID to sign up.