Found this in Redbook - it's a site listing organizations which need books. Many of them are in developing countries. I took a quick look - noticed some of them need relatively recent agricultural, science and veterinary medicine texts (among many other things). Perfect request for Sigma Alphas!
Might be an interesting service project for a chapter to round books up and pay the shipping! (of course, as the site mentions, contact the group first to verify details).
http://ublib.buffalo.edu/hsl/donationprograms.html