OurSignal is an interesting visualization that shows the current most popular stories from Digg, Delicious, Reddit, Hacker News and Yahoo! Buzz in one page.
Most Popular Tech Stories on the Web
The font size in the visualization is relative to the popularity of a story (bigger means more popular) while colors denote the trend – warm colors mean that story is increasing in popularity while cool colors indicate that the story is sliding off the charts.
What’s useful about OurSignal is that it auto-hides headlines of all stories that you may previously read in the browser. It does so by matching the web address of stories against URLs stored in your browser history and if there’s a match, it means that you’ve visited that link before and so it’s not shown in the the visualization map.
Stories on the OurSignal page are refreshed every 15 minutes so this could do as an interesting screensaver as well.