Compact fluorescent light (CLF) bulbs are a great way to save energy. They typically use 1/4 the energy of a normal light bulb, and that last for several years longer. But there is one thing to make note of when using CFL bulbs: they contain mercury. Mercury has all sorts of bad side effects if it gets into the groundwater, so you want to make sure that if you are using CFL bulbs you recycle them. The recycling process for CFL bulbs removes the mercury so that they can be safely disposed of. The good news is that Home Depot accepts old CFL bulbs for recycling at almost all of their locations and it is free to recycle the CFL bulbs. I don't usually toot the horns of large corporations, but it is nice that they are doing this since their stores are everyone which makes it easy for just about everyone to correctly recycle their CFL bulbs.