Many of your know about Philips Ambilight – technology to extend video action beyond the TV. Here is a Russian DIY analog of it. That project was started on 2006. Since that time the author made a few changes in the used hardware and software. Sure that DIY Ambilight cannot be a competitor of the Philips product. But as a concept it’s good and useful for understanding how Philips Ambilight works.
Here is also a ready-made device from site Ambilight 4 PC. It offers Ambilight effect for your PC.