Look at this!
What you need:
The Actual LEDs.
:
HDMI splitter 1in2out (or a compatible AVR)
HDMI to composite adapter. (if your HDMI Splitter/AVR does not have this feature)
USB Composite video grabber
A Raspberry Pi + 8GB sdhc card for the OS/Software
How does it compare to an actual Philips Ambilight TV?
Ambilight always emits white light in dark scenes (to be more eye-friendly)
Lightberry LEDs produce no light during black scenes on default but can mimic Ambilight if needed/wanted.
Additionally every TV (thanks to the raspberry pi) also turns into a Smart-TV and media center. Compared to Philips' ambilight, the Lightberry offers more precision and intense colors. Philips should really take a page of the Lightberry solution's book.
A downside is that you have to deal with a lot of cables and up to 4 power supplies compared to the Philips TV's 1 power cord.
You can also not use the Lightberry in conjuction with the TVs built in TV mode (Since you have to send a cloned image to your raspberry pi to get the light effects) The people behind the Lightberry are working on a solution but that wont be an easy task.
What do you guys think? Since I already own a raspberry pi (thats collecting dust for a year now) I think I will give this a try.