Via Dan Matthews, I actually think this isn't an awful idea.
That said ... wouldn't it be tremendously easier to simply have the appropriate governmental agency create an 'App' that would provide this information? Rather than reconfigure all of our cell phones, let's just utilize the existing technology and put it to work for us.
Still, not a terrible idea, and the fact I think something Rep. Paul Broun Jr. signed on to has potential is newsworthy in its own right.