Today's example of why Japan is different than us comes to us via Kazutaka Kurihara of the National Institute of Advanced Industrial Science and Technology, and Koji Tsukada of Ochanomizu University. Their project is officially called SpeechJammer, but it's promptly gotten a more widespread name: the 'Shut Up Gun'.
What you have is a directional speaker and a microphone, along with come computer parts. You point the Shut Up Gun at someone, and it will play their own voice back to them using delayed auditory feedback- you'll hear what you're saying about .2 seconds after you've said it. You know back when you were a kid and you and your sibling did the 'Stop repeating everything I say' game? That's basically what's going on here, in gun form. It'll do that until you decide to stop talking.
Unless you make a meaningless prolonged sound like 'aaaaaaarrrrrrgggh'. Then it doesn't work.
PC Mag also noted another well-known method of getting people to shut up: at awards shows, when they play off people whose acceptance speeches are starting to drag on. PC Mag did not note my favorite playing-off, that of the Ig Nobel Prizes.
The Ig Nobels utilize a little girl, who is called 'Miss Sweetie Poo'. When an acceptance speech starts to get lengthy, Miss Sweetie Poo walks right up to them and starts to repeat the phrase "Please stop. I'm bored." She will do this until the speaker stops boring her. In addition to working, it has the effect of being consistently hilarious.
But of course, you can't carry a Miss Sweetie Poo around all day. Or at least really really shouldn't.