Hi everyone, there's this website which AEN wants to recommend.
It helps people swap books on spirituality. Topics include non-duality, meditation, self-help, yoga, Buddhism, and so on.
Users post a list of books they would like to swap with others. You would send book(s) by post to a requestor, and likewise you can request books from others. It works by point system, so it's not necessary to do a reciprocal exchange. You are obliged however, to send off a book when the system allocates it to a requestor. Exchanges can take place internationally too.
Read more about how it works, as well as terms and conditions here.
http://www.spiritualseekerbookswap.com/page/howitworks