Developed by the Air Force, the so-called "Active Denial System" (ADS) fires out milimeter waves -- a sort of cousin of microwaves, in the 95 GHz range. The invisible beams penetrate just a 64th of inch beneath the skin. But that's deep enough to heat up the water inside a person. Which is enough to cause excruciating pain.

Seconds later, people have to run away. And that causes mobs to break up in a hurry. It's no wonder, then, why less-lethal weapon guru Charles "Sid" Heal calls the ray the "Holy Grail of crowd control."

Raytheon has been developing a Humvee-mountable ADS for the Pentagon over the last couple of years, as part of an ACTD, or "advanced concept technology demonstration."

By now, the system was supposed to be in the field. But there have been concerns that the ADS tests weren't sufficiently realistic. The Pentagon ordered additional trials. More than 2,370 ADS shots were fired during a pair of "military utility assessments" over the fall.

Now, the head of the Army's Rapid Equipping Force -- the unit in charge of getting gear to the troops in a hurry -- is saying: enough.

The system's "capabilities have, to date, been sufficiently demonstrated in the ACTD [advanced concept technology demonstration] to prove its value to the solider," Col. Robert Lovett notes in a memo, obtained by Inside the Army.

And the 18th Military Police Brigade has requested ADS "to help 'suppress' insurgent attacks and quell prison uprisings."

ADS' technical manager, Diana Loree, said the system "now meets all of the ACTD performance parameters," Inside the Army notes.

"Because the system is a hand-built, one-of-a-kind technology demonstrator, it does not meet conventional humvee curb weight requirements... However, the technology team worked closely with [Humvee manufacturer] AM General to ensure the safety of the system and its occupants."

There has also been talk, at least, of building an airborne model of ADS -- as well as putting together a Hummer with both pain rays and sonic blasters. Needless to say, neither project is as far along as the basic Active Denial System.