Ray Guns

Heat, death and many other kinds of ray guns are sci-fi staples. An early example is the Heat-Ray used by the invading Martians War of the Worlds, but you can hardly pick up pulp sci-fi without coming across some kind of ray gun. Now, some military lasers are capable of knocking out missiles. Non-lethal sonic guns, such as the Long Range Acoustic Device, will be used by soldiers protecting the 2012 Olympic Games.