Book swaps are an option, and can link in with reading clubs.

"We have to start seeing books in the same light that economists see money. That is, there is a large national or international amount which is in fluid supply. Occasionally, they are retained in one locality, but eventually they are released back into the stream from whence they came. Fabulous and important though money is, we're sure, knowledge, learning, information and entertainment: everything that books open to us, are of equal importance at least."

Check out this link: http://compostbook.blogspot.com/2011/11/books-on-tap.html