According to Wikipedia, over one billion people in the world live in slums. A slum, as defined by the United Nations is, "a run-down area of a city characterized by substandard housing, squalor, and lacking in tenure."
Perhaps you are wondering just who it is that doesn't know what a slum is, after all, the word carries enormous emotional freight, but as I listened to a piece on NPR this morning about the efforts of some residents of slums to use 21st century technology, GPS and satellite imagery, to literally put their homes on the map, it reminded me how skewed my perspective can be.
1200 square feet with electricity and running water? Don't mind if I do.