Did you know that lightbulbs are becoming illegal?

OK, nobody will raid your home in search of 100-watt subterfuge. But a broader energy savings bill that was passed and signed in 2007 indeed makes it illegal to sell inefficient light sources such as incandescent bulbs, starting with 100-watters in 2012 and ending with the smallest and dimmest bulbs in a few years. When the new rules take effect, starting in October this year, you'll have a hard time finding good old lightbulbs at the hardware store.

The giants of the old guard have already given up on the outdated technology. Philips (NYSE: PHG) says that "LEDs are the lighting of the future," and will only get cheaper as mass manufacturing ramps up. General Electric (NYSE: GE) shut down its last incandescent production line in 2010. The future is now.

So of course, there's a race for the new price going on. Who will sell the technologies that eventually replace the obsolete standard? Fluorescent tubes provide one obvious solution, but there are even better alternatives waiting in the wings.

LED lights are next on the list, as Philips notes, but they've been a bit too expensive for the average consumer so far. LED specialist Cree (Nasdaq: CREE) hopes to change those troubled economics with a smaller, brighter, and more cheaply manufactured lighting element.

The so-called XLamp XB-D platform offers twice the light efficiency per dollar, compared to the previous generation. That's cost efficiency for the lighting system manufacturer, not a lower power draw at the wall socket. But the XB-D is no slouch there, either: You get up to 136 lumens of light out of every watt of electricity pumped into the LED. A typical lightbulb delivers about 35 lumens per watt -- at best. To achieve the same light output as an old 100-watt bulb, you'd need about 13 watts' worth of Cree's finest light producers.

And there are others. Universal Display (Nasdaq: PANL) and lighting panel maker Lumiotec will start selling OLED lighting panels later next month, and they get 40 lumens per watt. In the long term, Universal aims for an energy efficiency of "more than 150 lm/W."

Who knew that boring old light sockets could be the place for exciting technology plays? I'm partial to the OLED story and recently bought Universal Display shares for my own portfolio. Other analysts prefer Cree. Don't be afraid to look in the tech sector for the best growth investments in 2012.