" The kind of intelligent book club discussion as now happens on the book sharing site Goodreads might follow the book itself and become more deeply embedded into the book via hyperlinks. So when a person cites a particular passage, a two-way link connects the comment to the passage and the passage to the comment. Even a minor good work could accumulate a wiki-like set of critical comments tightly bound to the actual text. "

― Kevin Kelly , The Inevitable: Understanding the 12 Technological Forces That Will Shape Our Future