I've put together a box of paperback books that I no longer want, and I've made a list of people who would like to play bookswap with me. Basically, you get the box, take out the books you want and replace them with your own books that you no longer want, log the information on the list that you find in the box, then mail it off to the next person. When the box gets back to me, with any luck, I'll find books I haven't read, but more importantly, I've passed along books I've already read.
A few points of interest: all my books are logged at http://www.bookcrossing.com/, so I expect people to make a journal entry on any of my books that they choose from the box. Usually people wait to make entries once they've read a book, but I need instant gratification that I've actually passed a book along, so I ask that the entry be made when a book is taken.
Postage for these boxes can vary, but they generally go media mail with delivery confirmation.
This box contains mostly paranormal romances, but there are books of other genres in it, too. You don't have to match genres, it's simply a one-for-one trade.
I'll have other boxes going out soon. One will be trade paperbacks, and one will be audiobooks on cassette and CD.
If this is something you'd like to do, please go to Bartered_Book@yahoogroups.com and sign up. Once I approve your membership, you will need to send me your mailing address so I can put you on the flight list. This box was supposed to go out a few weeks ago, but I'm notoriously poky about getting my boxes started. I will be sending it out next Thursday, the 9th of August.
Hope to see you there!