TVs that create ambient light behind the screen can make movie watching a bit more immersive, but they don't come cheap. Blogger Christian Moser decided the best course of action was to build his own with a Raspberry Pi.
Firstly, Moser got an ambient lighting setup working with XBMC and the Pi, then rigged up a system so he could split various HDMI inputs together. The end result is an ambient lighting rig that works with multiple HDMI inputs so he doesn't need to swap them out when he switches devices. It takes a bit of work to get everything up and running, but once it's set up it looks great. Head over to Techtalk for the full guide.