I made this a wiki too
A freecycle of sorts for media (books, cds, movies ect...)
A totally free service (except postage remember though it's cheaper then normal postage cause it's media postage) where you can list your old media and swap it for new (to you) media.
here's from their http://www.swaptree.com/WebFrmHowDoesThisWork.aspx
Is it really free?
Yep. It really is.
We don’t charge you for listing items or trading items. Nothing. Nada. Nil. Your only expense is paying the shipping of your item. Use the post office's Media Mail service and you can send almost everything for less than $2.50. Better yet, if you want, we'll try to find a trade for you with a swaptree member right down the street, or with one of your friends or co-workers, so you can just forget about postage and hand your item over in person. Now you aren't paying a dime!
How do I find trades?
Is it difficult to list items for trade?
Nope. Just need to read a few numbers.
Just enter the UPC or ISBN code that is on the back of every book, CD, DVD and video game, and we will find the correct item details: edition, release, version, paperback/hardback, normal/widescreen, etc.
That's the long answer to the question. The short answer: It's really easy to list your items.
Who has time to go to the post office to send an item?
Not us and certainly not you.
Because of that, we have made everything as simple as possible. We allow you to print accurate postage and perfect mailing labels directly from swaptree. So don’t worry about calculating the weight, or entering the correct shipping or return address – we do that all for you.
Just print a mailing label from your computer, put your item in your envelope, and place it in your mailbox. It does mean that you will have to get off of your couch, but only to walk to the mailbox.