Data visualization is one of the hot topics of the eDiscovery world. Dynamic visual maps showing the connections between documents or email recipients, can help attorneys bulk tag documents sets, and demonstrate to the others complexity and size of large data productions.
A good, freely available example of data visualization can be found at http://legex.org/process/index.html , the site of Legislative Explorer. Each node or particle on this site represents a different bill or resolution introduced in Congress - there is a particle for everything intoduced since 1973. Dark blue for Democratic sponsored bills introduced in the Senate; light blue for Dem bills from the House; and dark and light red for GOP Senate and House bilsl respectively. The user selects a particular Congressional session, and then clicks play to watch the progression of bills over time. The bills are clustered in groups according to the Congressional committees they are considered by, and you can watch bills fly back and forth between the two Houses as time goes by, and some land on the President's desk.
A glance at the visualization in the first screen grab below shows that most bills from both the House and Senate that are on the calendars or reach the floor or either chamber are Republican. It's a sign of our times, that there's just one lonely dot in the 'Became Law' section.
You can filter the data set by individual senators, representatives, topics, and even select an individual bill. Clicking on a particle shows a bill's number, title, sponsor, date of introduction, and 'ideology score'. The particle serves as a link to a page on the Congress's web site with the full text of the bill.
It's unfortunate that the site doesn't allow for visualizations comparing the legislative activity of groups of legislators, or the activity of bills on particular topics across different Congressional sessions. But it serves as a manageable, free demonstration of the basic concept of data visualization conveying information that everyone has an interest in. Legex also makes available a line and bar based interactive graph showing legislative activity over different Congressional sessions.