Newsmap
Newsmap is a very different type of Ajax application. It is a treemap based on the Google News aggregator. It takes a little getting used to, but it is very easy to see the biggest news stories (pun intended). Clicking on a story will open up the news source in a new window.
Categories are color coded included World, Business, Technology, Sports, Entertainment and Health. A legend allows the user to turn on and off their preferred categories.
There is also an excellent time based legend allowing you to select a timeframe over the last week available in Newsmap.
This is a Flash app… not AJAX