I really enjoyed looking through the sites, especially What Should I Read Next? and BookMooch.
BookMooch in particular reminded me of something near my Grandma's house in Connecticut. At the local trash yard there was a shed on the same property, and inside people brought all their old, unwanted books and could take as many as they wanted. Most, like my Grandma, would take a book, initial it after reading it, then return it for others to read.
BookMooch, the online Book Shed. Very exciting.