Ah, smartphones -- the delightful little slates carry our contacts, our content -- even our cash, and they still fit right in our pockets. No surprise then, that a lost or stolen phone can be a minor disaster -- or a major security risk (just ask the President). Now that soldiers are packing them to send GPS coordinates or situational images in the field -- on top of using them at home -- DARPA has enlisted security company Invincea to fortify the devices. Its first effort, encrypting OS files and filling the memory of a lost phone with worthless data, has already been deployed to 3,000 troops in Afghanistan. Its next target is to cloister apps into virtual rooms within the OS, locking off access to sensitive parts of the phone like its GPS or contact lists. That would keep any nasty bits of malware from potentially gaining root privileges so soldiers can fight, and Facebook, without compromise.