Since the government has banned most sales of incandescent lightbulbs, newer technologies like CFL (Compact Fluorescent) and LED lights have taken its place. There are plenty of reasons not to like CFL, though. The light they produce is harsh, they contain Mercury so there are pollution issues, and they take time to "warm up" after being turned on. LED bulbs, on the other hand, take very little power and last for a very long time. The only issue with LED lightbulbs at this point is the heat they produce, requiring a large and expensive heat sink to be used.
Leo has several Philips Hue RGB WiFi enabled light bulbs, which are cool because they can be set to not only provide accurate lighting conditions, but to mimmick light from any picture as well. The other night, however, Leo discovered a bug - when there's a power outage, it wipes out the programming and turns all the lights on full! He had left the lights on and turned them off with his iPhone app.