Since artist Candy Chang created the first wall on an abandoned house in her New Orleans neighborhood in 2011, more than 400 walls have gone up in the United States and more than 60 other countries, including Kazakhstan, Mexico, Iraq, Haiti, South Korea and South Africa.
In announcing The City 2.0, TED called on thought leaders such as Harvard economist Edward Glaeser, Whole Earth Catalog author Stuart Brandt, artist Candy Chang, green building guru William McDonough, and Robert Hammond, co-conceiver of the High Line in New York [http://www.thehighline.org/about/fri