I've been considering an Ambilight or Boblight system for a while now. I saw it on a television once it made quite the difference. I'm sure it'd be awesome on a multi-monitor setup. Though I think they're designed to attach to VESA moutns, adn I sue all of mine...
Philips made an Ambi-Light series of Plasma and LCD TV's. I had the Ambi-Light Plasma and it was awesome. Unfortunately they stopped making them about 4 years ago. Potential customers didn't see any value in it so they stopped making them.