Do you have dvds, cds, books or video games that you no longer need? Swaptree.com is a great service that allows you to enter items that you have to trade and enter items that you want. It is a free service that promotes trading between members. When Swaptree asks you if you want to accept a trade, you can either say yes or no. Once you agree to the trade, there's no backing out - the trade has to go through. Once both parties have accepted the trade, you can either print out a swaptree shipping label (shipping is charged to a credit card on file at the beginning of the month) or you can take it down to the post office. We like to use the online postage because it includes a mailing label with postage and delivery confirmation and you can print it in the comfort of your own home and put it out to be picked up with the rest of your mail by usps. It's like getting a "new or new to you" game/cd/book/dvd for the price of postage.
You can sign up free here: swaptree.com.
Note: Sometimes the person you are receiving your wanted item from may not be the same person you are sending your item to.