crosshatch brings us news out of Purdue University, where researchers are developing a radiation detection system that would rely on sensors within cell phones to locate and track potentially hazardous material. From the Purdue news service: "Such a system could blanket the nation with millions of cell phones equipped with radiation sensors able to detect even light residues of radioactive material. Because cell phones already contain global positioning locators, the network of phones would serve as a tracking system, said physics professor Ephraim Fischbach. 'The sensors don't really perform the detection task individually,' Fischbach said. 'The collective action of the sensors, combined with the software analysis, detects the source. Say a car is transporting radioactive material for a bomb, and that car is driving down Meridian Street in Indianapolis or Fifth Avenue in New York. As the car passes people, their cell phones individually would send signals to a command center, allowing authorities to track the source.'"