Just a wonderful example of data visualization, and what can be done with diagramming.
I first encountered Professor Hans Rosling talks on TED – really exciting. For example, see the recent talk about Religions and Babies where he shows what the world population will be, or the talk "washing machines" ("Even the Hard Core of the Green Movement Use Washing Machine"). I wish I had him as a professor when I studied in Uni =)
PS. Now the technology was acquired by Google, and is is available as part of the the project Google Public Data.