In the Smarter Than You Think book by Clive Thompson, he discusses what he calls, “marginalia”. As we read digital books, the comments from the smartest readers could become part of our reading experience and this could become a new type of public thinking. The Kindle, the Nook and other e-readers already allow readers to share comments and highlights in the text of a book.
I think it would be fun for people to read something together and be sharing comments as they go. I will explore this concept further. You can read about it here: http://futureofthebook.org/commentpress and there is also an app called bookship that looks very interesting. I would like to know if anyone has experience with these.