Look out, compact fluorescent. There's a new kid on the block, and compared to him, you're a dim bulb.
Ceravision, a British company, has developed a lamp that uses no filaments or electrodes. Instead, the Continuum 2.4 generates a concentrated electric field by bombarding a small lump of aluminum oxide with microwaves (diagram after the jump). Using the microwave tech, the continuum converts more than half of the power feeding it into light. Not perfect, but way better than the 15% efficiency of fluorescents or the pathetic 5% for incandescents.
Unlike a fluorescent, the Ceravision lamp uses no mercury, and the developers say it lasts thousands of hours. There's no word on when the product will come to market, but when it does, it just might ace out LEDs as the successor to the compact fluorescent.