OK, time to catch up on some of the news articles that have caught my attention recently. First we have a piece on a device called a Mosquito. The premise is simple; if you have groups of young people hanging around your home or business, and they are causing a nuisance, the device emits a noise that is unpleasant. Obviously this has become a little controversial, as one someone from the Liberty organization noted - “What type of society uses a low-level sonic weapon on its children?”
Click here for a video clip of the device, with the frequency lowered to ensure adults can hear it (as well as your soundcard being able to produce it 
)
I need one of those for my classroom. I could torture them and they wouldn’t even know it. Now if only they made something that made cellphone conversations inaudible, I’d be set!
You could have a go at writing (or finding) a Java-based tone generator for your mobile. However, whether it could get high and loud enough, I don’t know…
Re. cellphone conversations, you could just a jamming device, like some naughty cinema owners got caught doing in America!
http://www.freemosquitoringtones.org/
Mosquito Ring Tones by age group. I tried the “30 and up” tone, which I could just barely hear and I have a headache. It’s really annoying. Should work just fine to shut them up!
Low grade sonic weapons in use at Kazakh schools shocker. I can see the headlines now… Make sure you have some nice stock photos for Time magazine/FBI’s most wanted list