Although it isn't an auction site it aims to provide people a way to sell/swap or give away their unwanted items, promoting at least giving away rather than taking to the dump/landfill.  It's completely free and takes only minutes to create a listing.  There's no account sign up and listings are managed through a link which is emailed to the seller, the site also recommends that no funds are transferred online and that no items are posted, it's more of a Loot style site for bulky 'collection only' items.