Now, I've sold several of his books on Amazon.com. It's not making me rich or anything, but between the books he gave me and some books my Mom's got me selling for her (She lets me take 50% of the selling price, which is sweet!) I've probably made around $200. It's paying for my winter quarter textbooks at least :)
Amazon's fees are highway robbery, though. Too bad I am far too lazy to set up an account anywhere else!