Library Thing is another cool site that allows you to catalog your entire book library or just the books that you are reading. You can add tags or any type of headings that allow you to find the book in your catalog easy. Other people can see your library, and the site groups people together that may have the same or similar book interests. You can chose to keep your information private if you wish. You can review the books and read others reviews. Library thing will even recommend books that may interest you.