It's not the light saber from Star Wars; it won't cut the arm off a drunken Mos Eisley bar patron. But it sounds cool nonetheless:
The Department of Homeland Security is funding the creation an LED flashlight that uses powerful flashes of light to temporarily blind, disorient and incapacitate people. Homeland Security's Science and Technology arm hopes government agents can use the "light saber" to arrest people on planes and at the borders without using traditional weapons.
The LED Incapacitator uses a range-finder to measure the distance to a target's eyes and then unleashes continually changing, multi-color light pulses that both blind and disorient the person. Intelligent Optical Systems, a small company in Torrance, CA, is developing the weapon with money from Homeland Security's Science and Technology division, which thinks its possible to have the weapon deployed to cops, National Guard troops and border agents by 2010...
The tool could be scaled up to make a light bazooka that could subdue a crowd, but the company is focusing on miniaturizing the device to make it resemble a traditional D-cell Maglite. Right now the prototype is a non-svelte 15 inches by 4 inches wide.
This sounds cool, but remember the old maxim: Hokey religions and ancient weapons are no match for a good blaster at your side, kid.