Quoted: LibraryThing catalogs your books online, easily, quickly and for free.For book lovers, it's a LibraryThing: This site is similar to Del.icio.us, but for the tweed set. If you love books, and love people who love books, LibraryThing is for you. Start by using the service to catalog your book collection: Tag your books by topic, share your catalog with others, and then endlessly browse the titles that they have on their shelves. The utterly book obsessed can add the LibraryThing widget to a blog to show visitors what they have been reading lately. Listing up to 200 books is free; listing any number of books beyond that costs either $10 per year or a one-time $25 fee.