Stormreportmap.com

StormReportMap.Com - An Interactive Look at the Latest Storm Reports:
Yesterday leaving from Philadelphia my flight was delayed on the runway for over an hour because of storms between Philadelphia and Chicago. Thanks to stormreportmap.com I can visually see why they were holding us up. The site uses data from the Storm Prediction Center and hooks it into Google Maps to provide an interactive map of storm activity across the United States.

(Via Jon Udell's del.icio.us affinity feed)