We've seen every kind of speaker imaginable around the pages of CNET, but there is one type that. Parametric speakers focus sound using ultrasonic carrier waves for transmission. It's like a laser beam for audio.
You have to be in line with the speaker to hear what's coming out. Inventor Richard Haberkern is using Kickstarter to put parametric speakers into the hands of hobbyists, tinkerers, and geeks.
A fully assembled Soundlazer will put you back $175. A pledge of $275 gets you a spiffy aluminum case along with the kit. The components (like 39 piezo ultrasonic transducers) required to make the device are fairly expensive, hence the price.
If you get a Soundlazer, you'll want to use your newfound powers wisely. Use it at close range over 10 minutes, and you may damage your ears from the sound pressure.
Haberkern suggests pointing the Soundlazer at a wall or some other object to bounce the sound and avoid the direct waves if you use it in a tight space.
This brings us to the question of what you could do with a Soundlazer. I can see some potential as a cat annoyance device. You could broadcast secret messages to your work buddies or send your neighbor subliminal messages about cleaning up that overgrown front yard. It's too bad these won't be shipping in time for April 1.