Today on Smart City we're talking about communities. Real ones, and the virtual neighborhoods found online in such social networking sites as facebook and meetup.

Phil Wood is the co-author of "The Intercultural City, Making the Most out of Diversity." In it he describes the advantages of a diverse city, and how the interaction between intercultural groups can strengthen a community.

And we'll speak with Clay Shirky. He's the author of the book "Here Comes Everybody, The Power of Organizing Without Organizations." The book is about the power of the internet to break through old bureaucracy, and how online networking can create brand new ways of interacting out in the real world.