In our times, cityscapes are no longer dictated from above, by urban planners, architects, engineers— or even by geography — but "from below," by how the people live and work in groups. By simple, aggregated acts, people become spontaneous city planners: their urban design incorporates grafitti and street restaurants; makeshift homes that take their own formal pattern of development; ads and neon lights that become an integral part of the 'natural' landscape, as they have been for decades in Las Vegas. Even civic monuments can emerge, like the hundreds of names of desaprecidos "the disappeared" scratched in dirt in Buenos Aires. These changes are not accidents: they are "What We Want."

This kind of global transformation is not a dramatic force compared to erecting a skyscraper or residential housing – sometimes it is not even quite visible. But this force operates in strikingly similar ways in cities around the world; it is a profound social force in that it changes the way we interact and how we ultimately exert control over our environment.