Building a Better Light BulbThe race is on to develop the modern light bulb, but it may be that the modern light bulb won't be a bulb.
Incandescents -- The Old Standard Bearer
CFLs -- The (Relatively) New Kid on the Block
LEDs -- Closing Fast
Not So Fast, Mr. LED
Feel the Glow
(I found the article by going to the Scientific American website and searching "light bulb")