BookLamp is an early beta attempt at making a service like Pandora is for music, but for books instead.
Right now the site is limited in books and only gives recommendations for the book you select. At the moment, you cannot give a "thumbs up" or "thumbs down" like you can in Pandora. When I visited, BookLamp only had one book that I have read (that I can remember), 1984 by George Orwell. My feelings on whether I liked the book or not are mixed, and since that is the only book in their database that I have read, it is impossible for me to say how accurate their system is for me. They will have to add more books for me to know for sure.