The United Nations has a neat new interactive graphic up that visualizes the world's urbanization by country. At a glance, you can see what percent of a country is urbanized, and also how that population has grown (and will grow) between 1950 and 2050. Unfortunately, we can't embed it, but you can see the whole thing here.
Map of the Day: Urbanization in 15 Seconds
What the urban world will look like in 2050.