So you’ve finished the 759-page Harry Potter and the Deathly Hallows. Now what? Stick it on your sagging bookshelf to gather dust? Use it for bicep curls?

Swap it instead. At, you can trade books, DVDs, CDs, video gamesfor free.

Trading partially offsets environmental costs of printing millions of new books and discs, in addition to saving landfill spaceafter our short attention spans expire, these items often go in the trash. Worldwatch Institute reports that 45 tons of CDs are thrown away each month.

First, add an unwanted item to the list. Swaptree shows what you can trade for it. Browse the site and choose; trades are one-for-one. Swaptree calculates the postage and shipping; you can print labels from your computer, or handle the postage and labeling yourself. The person trading the item pays for shipping.