The future of lighting? The 'greener' 100-watt-equivalent LED bulbs are due to go on sale next year but are expensive. Although it sounds bad to pay as much as $50 for a light bulb, considering the fact that these LED light bulbs have an average life span of 25,000 hours (22 years) the price isn’t bad at all and if these bulbs would indeed last that long, this could really mean a technological...