Freecycle is a community of global groups sorted by location that helps people looking to re-use items either by giving them or receiving them. To quote from their website: "It's all about reuse and keeping good stuff out of landfills." To sign up is totally free and you get emails daily with posts of people looking for specific items like boxes, and people looking to get rid of items like say, a coach. You can look through their regional groups and sign up for your local chapter to start receiving posts immediately!
It's also a great source for us crafty people looking for bolts of fabric, old sewing machines, sergers, flex shafts - post your wish list, you never know what someone will be trying to freecycle!