Accoring to this Reuters story, the National Oceanic & Atmospheric Administration wants to build a system that could use cell phones or other technology to wake up sleeping Americans to warn them of tornadoes or other impending disasters.
Not a bad idea, but the fact is that the U.S. had such a system and it worked well for decades: the system of Civil Defense warning sirens built during and after World War II. These are still in use in tornado-prone areas and thoughout Hawaii, where they are part of a tsunami warning system. They remain very effective if very low tech. But in much of the nation, the warning sirens have been decommissioned. So now the government wants to spend who knows how much for a whiz-bang solution to a long-solved problem.