Ten years ago, the U.S. census enumerators carried paper maps to make sure each resident was counted. The maps were 3 feet wide and were unwieldy, to say the least. This year's census takers will carry something a bit more compact: a handheld GPS. Every single housing unit will be defined by its latitude and longitude.
You an watch a video about all this on the KCSG television station's web site at: http://www.kcsg.com/news/local/43074027.html?video=YHI&t=a.