The PHASR (aka Crowd-Blinding Rifle)
This futuristic weapon is being developed by the US military, who call it the Personal Halting and Stimulation Response rifle. Why such a clumsy name? Because they wanted to call it a PHASR. Get it! Like in Star Trek! How cute! There's no way this thing could turn out to be horrifying!
They also call these weapons "dazzlers," proving for the second time in two paragraphs that many weapons designers have never known the touch of a woman. It projects a laser and is intended to "dazzle" and temporarily blind the target. It's kind of like one of those annoying laser pointers crossed with the BFG from Doom.
Why It Won't Kill You:
According to the makers of the weapon, when used properly it doesn't, under any circumstances, kill you or do any lasting damage. The beam temporarily blinds bad guys so they can be arrested, or they can be set up as a perimeter defense to keep an attack at bay.
Why You'll Wish it Had:
Ever went for a piss in the middle of the night, walked into the bathroom and turned on the light? Hurts, huh? Well this thing is many hundreds of times more powerful, and specially designed to project a wavelength that's most effective at short-circuiting your eyeballs.
Not many other nations are developing this technology. Now, this could be because the US military is far superior to those of the rest of the world. Or it could be that the 1995 Protocol on Blinding Laser Weapons banned lasers and the US military just couldn't give a fuck about international weapons bans.
The ban came after concern from humanitarian groups, something about potential crowds of blinded refugees wandering around in a war zone and slowly starving to death. So the PHASR developers just turned own the power enough to skirt the ban.
The problem is that they still had to make it powerful enough that even the biggest badass enemy soldier would still go running the opposite direction, screaming and clutching his eyeballs, but that it somehow wouldn't do any damage to an innocent toddler's still-developing retinas. Seems like kind of a fine line there, but we're sure they know what they're doing.
The Active Denial System (aka Massive Pain Ray)
The Active Denial System (ADS) is a giant heat ray (or pain ray as it's informally and less ambiguously known). The weapon fires electromagnetic radiation at the target causing a painful burning sensation.
It can penetrate through layers of clothing, though apparently can't pass through thick metal such as a trash can, so basically Oscar the Grouch should be fine but Big Bird is fucked.
Why It Won't Kill You:
The military says the ray only causes the impression of burning (they say your hair won't actually catch on fire, for instance). The ray just barely penetrates the skin, just enough to make your nerve endings think you're on fire. To prove this, they often invite people to stand in front of it.