Wall light switch timers are an easy way to save on your home energy bill. They automatically turn a light switch off after period of time that you program into the switch. The problem is that not all are compatible with compact fluorescent bulbs, which will be in most homes in a few years as incandescent bulbs are phased out by federal law.  If you want to save enery a wall light switch timer can pay for itself in about a year, as seen in the example in the following article: