PaperBackSwap.com - The paperback swap table in the lobby of your local library might have several dozen books, but it's almost always hard to find something you really want. This website puts nearly a half-million books on that table, makes it searchable and lets you trade for the price of shipping. Here's how it works: List at least nine of your own paperbacks on the site, then start receiving book credits for each one you mail to another member. (The shipper pays the $1.59 postage.) Then browse the vast library and start having paperbacks shipped to you.