And I don't like the idea of this thread below this at all. I even think it's very much a part of the problem, not its solution. Of course, it's happening, all the time, people moving from "ugly" and crowded city, somewhere to a "countryside" (yet near the city). And that's why I can't go anywhere outside the city, because there ceased to be any outside, just ring after ring of satelite villages, and roads between them. It had also turned the city into just a little more than a large parking place...
From http://www.unfpa.org/swp/2007/english/introduction.html
Quote from the introduction
In 2008, the world reaches an invisible but momentous milestone: For the first time in history, more than half its human population, 3.3 billion people, will be living in urban areas. By 2030, this is expected to swell to almost 5 billion. Many of the new urbanites will be poor. Their future, the future of cities in developing countries, the future of humanity itself, all depend very much on decisions made now in preparation for this growth.
(To put up a disclaimer, I have just extrapolating this from what I think. I have not done a significant amount of research. There is a lot science fiction talking about this however, such as Daemon, Freedom TM, and even The Stars My Destination from way back. I also found this article that has some facts, despite being a little old. http://www.innserendipity.com/ruralren/rebound.html)