Jack Bauer Cellphone Network to Detect Nukes, Surveil City

Scientists and industry have been working together to create a global surveillance network. It naturally weights itself to provide greater coverage for greater populations, contains more distributed computing power than the entirety of NASA, doesn't cost a single tax dollar and people waste it all talking about 'Lost'. Yes, you and your cellphone friends are part of one of the most powerful network in the world and researchers at Purdue University have found a more important use for it than arguing about where to eat lunch. Their design converts your local coverage area into a vast radiation detection grid, capable of thwarting the modern-day boogieman of nuclear terrorism once and for all. You might think adding a directional nuclear detection rig to your handset would make it even more expensive than an iPhone, not to mention ruining the line of your pocket, and you'd be right. The key to the system is the universality of mobile phones throughout the civilized world - rather than complicated detection components, a simple, light and very cheap "hotter/colder" solid state sensor in each handset is enough...