Enormous quantities of data go unused or underused today, simply because people can't visualize the quantities and relationships in it. Using a downloadable programming environment developed by the author, Visualizing Data demonstrates methods for representing data accurately on the Web and elsewhere, complete with user interaction, animation, and more.
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Visualizing Data teaches you how to answer questions, not simply display information.

Looks like a damn cool book...

I've played around with the Processing language and tools a bit and found them really cool. I've been particularly impressed with Jared Tabell's work on generative art using Processing...

Very worth checking out.

Visualizing Data, by Ben Fry