I've just stumbled across EagerEyes and found lots of interesting discussion and examples about data visualization. The post that caught my own eager eyes was about this image:
The author, Robert Kosara, describes it like this:
What would happen if you were to connect all the ZIP codes in the US in ascending order? Is there a system behind the assignment of ZIP codes? Are they organized in a grid? The result is surprising and much more interesting than expected.
There is lots of great content here and links to several more interesting blogs that were new to me also.