Using light-emitting diodes, the new bulbs from Osram Sylvania use 20 watts and cost $50. They are designed to fit regular light fixtures. However, the bulbs are slightly larger than regular bulbs, so they may not fit in all lamps.
Osram's bulb is in limited release at some Lowe's stores, but competitors aren't far behind. Philips plans to start selling its own, slightly brighter 100-watt equivalent on Home Depot's website starting in a few weeks for about $55.