HDMI-CEC

[Rene]

HDMI-CEC is the protocol used to control devices connected over an HDMI link. There is already a device which you hook onto an USB port on one side and an HDMI connection on the other side and so provides the ability to control all devices interconnected via HDMI which support HDMI-CEC. See here for more information on this device.

[Esteban]

Nice find and very affordable, unlike some other devices.

Here are a couple more CEC devices/stuff I'm aware of:

This one:
http://rainshadowtech.com/default_files/HDMICECUSB.htm
http://valkyriemt.wordpress.com/2010/07 ... tra-wires/

The nice but very expensive:
http://www.kwikwai.com/product.php
(two more vids after the jump)

And there are also some arduino projects I've seen with CEC.
http://www.arduino.cc/cgi-bin/yabb2/YaB ... 61237176/0
http://code.google.com/p/cec-arduino/

[Snelvuur]

You can better have a look at http://xbmc.org/natethomas/2011/11/01/t ... he-future/ if thats what you might be using it for.