On Star Trek, a phaser (left) could stun life forms or kill and vaporize them, depending on the setting.
Last year, the U.S. Air Force released information about and this photo of a PHaSR, or Personnel Halting and Stimulation Response system. It is a prototype laser weapon that generates light capable of temporarily impairing a person's vision. The prototype is obviously much larger than the Star Trek version, but the concept is there. And don't forget the Taser.