As previously reported on sister site Gizmodo, the SpeechJammer is a gun that "jams" people's speech, by firing their words right back at them within milliseconds of being said.
In the above video, the wizards at the National Institute of Advanced Industrial Science and Technology in Japan show how the gun works. Shame it doesn't come outfitted on game consoles—or maybe that's a good thing.
If only they'd develop a gun that silences stupid forum comments!
SpeechJammer (en) [YouTube]