Bob installed the Engen software on a Raspberry Pi this week. It can be used to control lighting. It also runs Media Center.
The peripherals are almost bigger than the Pi.

On the left is a Z-Stick. It's a controller for Z-Wave devices and Engen manages it. The Z-Stick is a transmitter. The receivers are built in to special light switches, outlets, and light bulbs.
To its right is an Audioquest DragonFly USB DAC.