Researchers at the Alaskan Volcano Observatory are using Google Earth to monitor the risk of an eruption.
Project leaser John Bailey used Google's KML (Keyhold Markup Language) to create a custom program that displays eruption risks within a specific area. According to Wired News, "The program analyzes the data, assesses a threat level and displays the result as a triangular icon. An orange triangle, for instance, indicates an elevated threat level, while a red triangle means a greater threat, namely a current or upcoming eruption or other activity."
The U.S. Geological Survey office will be making a Google Maps version of Bailey's application soon.