Cell-Phone Zapper

I am not a wuss. And yet I've never told people to pipe down when they were disturbing my peace with their too-loud blatherings on a cell phone. I let them disrupt my naps on the morning train. I even turn the other cheek in restaurants or at the movie theater. Instead, I quietly simmer, indulging violent fantasies that involve the loud-mouthed caller's being stranded in a swamp with nothing but his cell phone and a starving, 1,200-lb. alligator named Big 'un.

Recently, though, I came into possession of what may be the ultimate weapon for people like me who hate...