Smart Glow: Light As Your Data Carrier

This is a very poetic 21st century idea, and it's not at all difficult to implement even for a DIY hobbyist. What will be expensive is speed here. If you want really fast bandwidth, your light sensors will have to be those with microsecond, even less, response time to optical stimulus, and the everyday LDR will not suffice. Especially for slow homebrew projects, though, it would be so hypnotic to simply watch it in action. At fast transfer rates, you'd never notice what's going on.

In any case, a completely original idea:

"Imagine if your computer, iPhone, TV, radio and thermostat could all communicate with you when you walked in a room just by flipping the wall light switch and without the usual cluster of wires," said BU Engineering Professor Thomas Little. "This could be done with an LED-based communications network that also provides light - all over existing power lines with low power consumption, high reliability and no electromagnetic interference. Ultimately, the system is expected to be applicable from existing illumination devices, like swapping light bulbs for LEDs."

Boston University researches will focus on developing computer networking applications, notably the solid state optical technology that will form the network's backbone.

"This is a unique opportunity to create a transcendent technology that not only enables energy efficient lighting, but also creates the next generation of secure wireless communications," Little added. "As we switch from incandescent and compact florescent lighting to LEDs in the coming years, we can simultaneously build a faster and more secure communications infrastructure at a modest cost along with new and unexpected applications."