Social networks can bring people together and even fuel revolutions. From Twitter to Facebook, from Orkut to Myspace, social networks online have linked millions of people of wildly different stripes.
But what happens when you base social networks on a specific community, in this case book lovers? And what happens when publishers and booksellers such as Amazon get in on the act?
Here are six social networking sites that are up and running now, and we'll tell you the difference between the ones with book publishing interests and those tied to other interests.
We'd love to hear what you think of these sites and if you're a member of any of them, tell us about them in the comments section or vote in the slideshow below.