Data visualizations can be used to tease out and illustrate trends from data in new and unexpected ways. Timothy Noah over at Slate introduced the concept of "the Great Divergence" and then he used a data viz to take readers on a visual tour of income inequality in America.
Visualizing numbers can add context to any story. Last but not least, we have a viz by Information is Beautiful's David McCandless. It's called the Billion Dollar-O-Gram and is an interactive tree map. He created this viz out of frustration with media reports citing billion-dollar amounts without providing the proper context.
Data visualization is taking the web by storm and, with a little luck, it might be the next big thing in online journalism. Buoyed by the open data movement and accelerating change in newsrooms around the country, it has become something more than just flashy graphics and charts -- it is a new form of visual communication for the 21st century.