The first practical use of the light emitting diode (LED) was introduced in the 1960’s. You may recognize one as the bulb in your flashlight or fun little things that come in your Arduino Starter Kit (that’s what I first think of at least). Just what is an Arduino [click to find out] and here are some cool things you can do with it. Anyway, be on the lookout for the new LED light bulbs. They are suppose to be more efficient than and have approximately 20 times the lifespan of incandescent bulbs. What about compact fluorescents you ask? Are the LED bulbs a threat for them too? Well, not exactly.
Right now the cost of one LED bulb hits your wallet at about $60. The price is estimated to drop by two-thirds in 2013. Currently, a compact fluorescent bulb is significantly cheaper and is proven to last at least 10 times longer than an incandescent. Personally, I like the lights I have to work/read under to be very bright, 75w+. LED bulbs will be available in 40w and 60w (for now).
Unlike compact flourescents though, LED’s will not require specialized disposal, nor do they run the risk of you being exposed to mercury if broken. In terms of monetary savings: productdose.com conducted a study comparing compact flourescents to LEDs. The conclusion? It all depends on the energy rate of your area. They provide an Excel spreadsheet to help you figure out your savings.
SpotCoolStuff has a list of the Next Generation of LED Light Bulbs
Inside My Head 