Fluidic amplifier/hydraulic transistor

It's a fluidic amplifier. A small stream of fluid deflects a large stream, in effect, amplifying a pneumatic signal. If you want more details, I wrote about it in my blog:

http://mymakerblog.wordpress.com/2013/05/28/fluidic-logic-and-3d-printing/

You can test it by holding the pieces together and blowing simultaneiously into the power port and one of the control ports. It's pretty freakin amazing that it works. :)

I should also mention that this has already been patentedin 1974:

http://www.google.com/patents?id=tZAzAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false