The Satellite Sentinel Project is an initiative that uses commercial imaging technology from Google and DigitalGlobe to track possible human rights violations, and has already turned up evidence of mass graves and war crimes in Sudan. It all sprung from an initial idea by actor-turned-activist George Clooney, who tells the LA Times that the project avoids international incident by bypassing diplomatic routes and directly taking satellite images as private citizens. Check the link for more, including what Clooney learned from Bono about being a celebrity with a cause.