You forget the fact that there are a lot of people - a lot more than there are not - that have no grasp on modern technology, modern government, and modern culture. Cultures that have been living off of bugs and sticks for 500 years aren't exactly going to mix well with cultures that have cars, planes, computers, and electricity.
Plus, there's the language issue. Almost every single person would have to learn a new language and new customs. It's not easy, by any means. You can't just teach these people in a classroom how to cooperate efficiently.
And then there's the matter of assigning all these people jobs. For example, whilst people who are doctors and scientists can go pretty much anywhere, people who are machinists can't just go into the middle of Africa and set up shop.
And finally, there's the issue of government. You can't just assign Newt Gingrich, Barack Obama, John Mccain, and Rush Limbaugh to govern the same city. People aren't just going to drop their views on issues just because they've been thrown into a new environment. Plus, how would these people know how to govern a whole new demographic of citizens?
It's a good idea in theory, but then again, so was Communism.