I had to replace some lamp bulbs at home, and while buying them, I found out that the price of compact fluorescent bulbs went down quite a bit compared to some year ago. With six dollars I bough four compact fluorescent lamps producing 1600 lumens each, with a power consumption of 23 Watts, compared to the 100 Watts required by a normal incandescent lamp to produce the same light.
The quality of the light is good, very similar to the light produced by incandescent lamps. If the energy saving effect is summed up to the longer life cycle of these lamps (one lamp is supposed to last for 9 years, if used for three hours per day, according to the manufacturer), the amount of money saved is not negligible, exactly as it is not negligible the reduction of the impact on the environment.
One last note: to avoid contributing to pollution, these lamps must be disposed correctly, because they contain mercury. Information on handling the lamps vary from place to place, so it is worth to look for information specific to your location.