"A Voronoi diagram divides the drawing into regions around each point that are shaped so that the borders of the regions are equidistant from the two nearest points. It's kind of the vector equivalent of grid mapping where you're trying to show boundaries of influence from point data."
Reading Assignment - We will finish The Ghost Map on December 23.
http://mappae-mundi.blogspot.com/2010_10_01_archive.html