The wisdom of dead crowds

bill thompson just wrote a nice article on eternity on the web, and namechecked a talk by steven johnson about the superb book, Ghost Map, which relates the history of Snow and Whitehead and their seminal comprehension of the cholera epidemic and its progress through voronoi diagrams of people's from houses with and without victims, walking distance from infected and uninfected water pumps. Johnson coined/modified the term
"the wisdom of dead crowds"

of course, being pedantic, I'd point out that the good doctor and reverend were smarter than that - they used both the living AND the dead to do the maps thus making this one of the most elegant pieces of scientific research I have ever read of.