First time accepted submitter iinventstuff writes "The Idaho National Laboratory has built a dirty bomb detection network out of cell phones. Camera phones operate by detecting photons and storing them as a picture. The INL discovered that high energy photons from radiological sources distort the image in ways detectable through image processing. KSL TV reports that the INL's mobile app detects radiation sources and then reports positive 'hits' to a central server. Terrorists deploying a dirty bomb will inevitably pass by people carrying cell phones. By crowdsourcing cell phones, the INL has created a potentially very large, inexpensive, and randomly mobile radiation detection grid."