Read on for a look at some of these futuristic weapons being tested today.

Photo courtesy U.S. Army

The XM-25 grenade launcher is equipped with a laser rangefinder and on-board computer. It packs a magazine of four 25mm projectiles, and programs them to detonate as they pass by their targets. That feature will allow soldiers to strike enemies who are taking cover. By 2012, the Army hopes to arm every infantry squad and Special Forces unit with at least one of the big guns.

In August, a lucky soldier got to pull the trigger, and fire off a HEAB, or High Explosive Air Burst, round at the Aberdeen Testing Ground in Maryland. Those projectiles pack quite a punch. They are purportedly 300 percent more effective than normal ammo, and will be able to strike targets as far as 700 meters (2,300 feet) away.

Photo courtesy QinetiQ North America

Remotely operated weapons are showing up everywhere. Israel is building an automated kill zone. An American firm, More Industries, offers a turret that can aim and fire two automatic shotguns.

Some bots have been defusing bombs for years, but none have seen combat. That’s a shame, according to Lt. Gen. Rick Lynch, who believes that 122 men could have been spared if combat bots had been working in their stead.

There was a set of armed robots sent to Iraq. They never fired a shot, however. They weren’t allowed to. No one could guarantee that the bots wouldn’t go berserk and mow down friendly troops or otherwise malfunction, even though they have lots of safeguards.

Considering how much firepower they pack, safeguards are really important. The Maars system (above) can be equipped with four grenade launchers and a machine gun that packs 400 rounds of 7.62 caliber ammunition.

But its manufacturers like to point out its less-lethal capabilities. Instead of mowing people down, it can stick to the fine print of the first law of robotics and fire tear gas canisters, smoke grenades, smoke bombs and perhaps even Taser’s upcoming 40mm people-zapper projectile. Three were deployed to Iraq last year.

Photo courtesy U.S. Army

The Active Denial System fires a beam of millimeter-wave radiation. It make people feel like their skin is burning without causing any permanent damage. Though promising as a nonlethal weapon, the pain ray has some serious limits.

On a rainy day, water droplets will disperse the beam, and it may feel warm and refreshing instead of frightening. On a hot day, the cooling system might give out. The problems don’t stop there. Raytheon’s baby is bulky, and despite repeated requests to send it into battle, shipments of the energy weapon have been delayed. The military is looking for a stronger, lighter weapon.

Photo courtesy U.S. Marine Corps

If troops spot someone suspicious approaching them, they can use the Long Range Acoustic Device to send a warning message. It fires narrow beams of sound waves that can be heard clearly from 300 meters (about a thousand feet) away. Crank up the power, and it can emit a warning tone so loud that anyone in its path would have no choice but to cover their ears and run.

The manufacturer doesn’t like to call these devices weapons, even though they’ve been used to repel pirates. Cops used them to harass protesters at the G20 summit in Pittsburgh this year.

Photo courtesy Bryan William Jones

Photo courtesy of Bryan William Jones

Drones are arguably the most controversial weapon in the war on terror. By some accounts, they aredeeply feared by the Taliban.

They’ve taken out many Al Qaeda and Taliban leaders, and their sound when flying low is a constant annoyance and a reminder of their menace . But they also kill a lot of civilians.

They are, however, far more cost effective than supersonic fighter jets. Predators can pack two Hellfire missiles. Their big brothers, Reapers, can hold four Hellfires and two 500-pound bombs.

Photo courtesy Sandia National Laboratory

Flash bang grenades were designed to stun people. But they have a pretty bad safety record. The little bombs have dismembered at least one soldier and caused hearing loss in others.

To remedy that problem, Mark Grubelich and his colleagues at Sandia National Laboratory built the Improved Flash Bang Grenade. It hurls flaming aluminum particles into the air, causing a bright flash without an accompanying shockwave.

Photo: Pat Shannahan/Wired.com

Even the angriest mobs would probably think twice about trying to pass a Taser Shockwave barrier. It is the less-lethal equivalent of a claymore mine. Push the big red button, and it will fire 24 electrified probes at the same time in a single direction.

Photo courtesy Bedazzler

After learning about an experimental weapon that can make people feel seasick, Limor Fried and Phil Torrone decided to build their own. They did it for less than $250, and wrote step-by-step instructions so that anyone can make one at home.

It can create a nauseating lightshow with 36 pulsating LEDs.

Their design has a bonus feature. You can set it to disco mode. Instead of making you sick, the weapon will add life to your next party.

Photo courtesy B.E. Meyers

If you’re worried that someone’s about to attack you, but not completely sure of their intent, it’s a good idea to give them a warning before pulling the trigger. Green laser pointers are a great way to extend that courtesy. The Marines like to call them “ocular interruption devices.”

Shine one in someone’s face, and your target should immediately get the message that it’s time to back off. The LA-9/P, made by B.E. Meyers, can warn people from up to 4 kilometers (2½ miles) away. It fires a 250-milliwatt beam. That’s roughly 1/4,000 the strength of the smallest anti-aircraft lasers.

Even so, you’ve got to be careful when handling the thing. Over a few months in Iraq, a dozen soldiers were wounded in dazzler “friendly fire.” Several troops may have been injured while monkeying around with laser target designators, which are substantially more powerful than the less-lethal devices.

Photo courtesy Boeing

Behold the Laser Avenger, a cannon that could be used to take down incoming aircraft. Boeing was able to shoot a drone out of the sky with the hummer-mounted laser, even though it’s not particularly high-powered. It cooked the remote-controlled aircraft using a somewhat feeble 1-kilowatt beam.

More recently, the company shot down another UAV using a low-power laser paired with its Mobile Active Targeting Resource for Integrated eXperiments, or Matrix, system during a test in White Sands, New Mexico.

Northrop Grumman is hard at work on a 100-kilowatt laser weapon, which could do far more damage, but it’s not quite ready for prime time. It’s fully operational, but looks like a refrigerator.

Boeing announced in late December that the Avenger has been used to destroy 50 different improvised explosive devices, during tests at Redstone Aresenal in Huntsville, Alabama.