Newsmap is an effective visualizer of Google News stories that creates treemaps based on the volume of stories for each topic. The interface allows you to compare different national news sets and to show/hide different types of news (world, nation, business…). What’s more, it actually works visually and for looking at the information.
I had never been convinced by treemaps such as those Ben Shneiderman demonstrated, but now I am. Can this be used to visualize a text?
A quote from the site:
Newsmap does not pretend to replace the googlenews aggregator. It’s objective is to simply demonstrate visually the relationships between data and the unseen patterns in news media. It is not thought to display an unbiased view of the news, on the contrary it is thought to ironically accentuate the bias of it.
For more on treemaps see Treemap: Home page.