Perhaps you'd like to share your books with others? Maybe you'd like to offer up your own opinions on books to an erudite audience? Both of these things can happen with Shelfari. The site allows members to build virtual bookshelves, discover new books, and also participate in online book groups. Visitors can sign up for a free account and get started right away. It's easy to see how students might also use this feature in a classroom setting, and Shelfari is compatible with all operating systems.