I first encountered the concept of an infographic when I attended Edward Tufte's seminar "Presenting Data and Information." Tufte is an expert in "the graphical display of quantitative information" and also an artist. This seminar introduced me to the idea that data should not only be accurate, clearly communicated, and useful, but it should also be beautiful. It seems that idea stuck with me...
Tufte's favorite example of a great infographic is "Napoleon's March to Moscow" from 1869. It's a map showing Napoleon's route to Moscow and his subsequent retreat. It is not only beautifully designed but also includes data on the weather (it was very cold) and the casualties in his ranks. It looks like this:
(larger view here)
I love beautiful art that communicates interesting data. Next month, Christie's will be auctioning bottles of port alongside a map of the Douro Valley in Portugal. This map by artist David Eley illustrates all the primary winemaking estates and "flora and fauna" of the area. It's beautiful and educational and communicates lots of information. You can see a larger version of it at the link above, but here's a preview:
I think Tufte would approve.