The patented Map of the Market feature from SmartMoney (this view shows Aug 8, 2011) shows more than 500 stocks at once, in rectangles sized in proportion to their market capitalization, and colored green or red according to latest trading activity, up or down.
The visualization is derived from work done by Prof. Ben Shneiderman and students at the University of Maryland Human-Computer Interaction Lab on treemap displays.
Category: Digital Artifacts
Visualizations, works of digital art, and other finds that show creative and powerful use of data and presentation.
Americans rate their representatives in Washington (word cloud)
From the Pew Research Center for the People & the Press, July 2011, during the budget-ceiling debate in Washington. 
30 years of music industry change, in 30 seconds….
This animated chart, from digital music news, shows strikingly the changing contribution of vinyl LPs, CDs and other formats to music industry profits over the past 30 years. 