Among the other fabulous tips I get on my favorite news-lite morning program, here is a fun site I found on The Today Show: www.swaptree.com
Swaptree let's the swap your old books, dvds, and cds you have for the ones you want! The site hooks you up with someone else in the U.S. who has what you want if you have what they want. You don't have to dig and search like on ebay. All you pay is shipping! So far I listed some of my books and dvds, just waiting to see if there are any bites.
Some other sites include: zwaggle.com (baby stuff) or freecylce.com (gets rid of stuff for free).
have fun! let me know what you think.