I added Google Now voice commands to my Raspberry Pi and Arduino powered LED Coffee Table that I built at the DMS awhile back.
The LEDs are hooked up to an Arduino for direct control, but the Arduino can also be connected to a Raspberry Pi which communicates over USB serial.
The RPi is running a Java program I wrote with a webservice. It can change the Arduino modes or push out raw color info to it as an array. This allows it to display small images or make animations from a folder of images.
This weekend I set up some Tasker scripts on my phone to hit the RPi webservice and used the Tasker plugin AutoVoice to get voice recognition through Google Now. This means I can call scripts and change display modes with voice commands.