via Eyebeam reBlog:
Newsmap is an application that visually reflects the constantly changing landscape of the Google News news aggregator. A treemap visualization algorithm helps display the enormous amount of information gathered by the aggregator. Treemaps are traditionally space-constrained visualizations of information. Newsmap's objective takes that goal a step further and provides a tool to divide information into quickly recognizable bands which, when presented together, reveal underlying patterns in news reporting across cultures and within news segments in constant change around the globe. newsmap
The principles are clearly explained by this posting on Boing Boing:
Newsmap is an application that visualizes the totality of the GoogleNews aggregator — an amazing piece of software which not only aggregates almost every single online newspaper, but combines news stories into clusters so that when the same story is repeated among several news sites, it files and displays only one to you - no mater how different the actual text that makes the article is. Google news aggregates stories in several languages and customizes its content for 10 particular countries. I've loved googlenews for this particular reason since the first day, and it was then when I started thinking about visualizing the totality of it, since it could be a very close approach to getting a picture on how news media attention differs from country to country. Newsmap utilizes a treemap algorithm to dynamically create each view, and the size of each cell is determined by the amount of related articles that exist inside each news cluster.