paperbackswap.com. If you're not familiar with it, and you are a book lover like myself, you really should check it out. I rounded up all the books that were not really necessary essentials to our family library, and not ones I could sell to other homeschoolers, and posted them as available for swapping. This has been a great way for me to make both my husband and I happy. I purge some books from the house, and I wind up with others that I can own and read - at least for a time until I might swap them out again. Others I wind up keeping for good. Overall, even if I don't wind up with as much available shelf space as my husband would like, I am saving money on my books. For the price of shipping, less than $3 most times, I have a new one. And for voracious readers like myself (and maybe you), it's a definite win.