The first commercially used LEDs (light emmitting diodes) were developed in the 1960's. They were limited in their application because they could only produce a low level of red light. Since then the technology has developed tremendously. No longer consigned to lighting calculators, cats eyes or car headlights they are predicted to take the residential lighting world by storm.
The good quality LEDs now do everything the incandescent bulb can do but better. They produce the same 'warm' white light, can be dimmed and come in different beam angles. But that's not all, they last longer, are cooler to touch, and importantly, are far more efficient. An LED will typically produce the same amount of light with a quarter of the wattage (energy).
Sadly, at the moment, they are relatively expensive. I'm confident, though, that the price will reduce over the coming years (just as the price of PCs fell in the 1990s). Nonetheless I'm recommending them now wherever the budget allows as they are a fantastic solution for those of you who are keen to be energy efficient.
Why not call up and get more details.