Control a Pneumatic Valve from the NXT.
Courtesy of Jim German of Motocube.
Using the Sensor Building Kit for NXT with PCF8574 IC, the SN754410 from Texas Instruments and some fancy wiring, Jim was able to control a Pneumatic Valve from his MINDSTORMS NXT.
While Jim mentions that this design could be improved (it requires a 24v power supply for starters) it is a good proof of concept. I can see a new range of home-grown pneumatic robots taking over the world... or the living room.
The full writeup is found here: Pneumatic Valves via Motocube