Sign up here to trade DVDs, CDs, paperbacks, videogames and more. The only money that changes hands is the $1 fee you pay the site for each successful trade. Choose a screen name and you're ready to swap; it's easy to post the items you want to trade; you simply plug in identifying information, like a UPC code on the back of a CD the site walks you through this and the site produces the full listing. You can search for items you'd like to have, and send messages to the owner, indicating your interest. Trade offers pop up as "zunalert" messages on your personal Zunafish home page. Since the site launched in January, "thousands" of trades have been consummated, according to a spokesperson. (We received an offer for our own remaster of The Who's Live at Leeds within just a few hours of posting it but what to select in exchange? Best of Bad Company? The Immaculate Collection...?) SwapSimple, based in Chicago, works a similar angle, but while Zunafish requires like-item trades only (a book for a book, a DVD for DVD, etc.), SwapSimple allows you to mix and match media. It's particularly popular among college students, who use it to trade expensive textbooks.