Metafilter links to and discusses to an interestin
g article in EE Times about a researcher at Rensselear Polytechnic Institute wh
o claims to have [invented a 99%-efficient omnidirectional reflector that will
allow LEDs to replace light bulbs](http://www.eetimes.com/at/news/showArticle.
jhtml?articleID=25600144). Since lighting accounts for about 25% of US energy
use, efficiency gains here can have a huge impact. NSF and ARPA are bankrolli
ng the research, and the research team hopes to commercialize the technology in
three to five years.
Wikipedia has a [nice general background article on LED technology](http://en.w