I have been head down this week doing the R2 End Stage report for my current Android project but I had a chance to read this fascinating article. If you are not familiar with the concepts of the social net this forms a good introduction to many of them.
Quora is a booming Q&A site. It just might be the next big social media site to cross the chasm and go mainstream. It is certainly booming right now, and is the darling of tech watchers. But unlike other recent Valley favorites like FourSquare (narrow appeal) and Groupon (for shopaholics), Quora might well become as fundamental to the Web as Google, Facebook or Twitter. Everybody asks and answers questions after all.