Daylight savings time was implemented by Congress to conserve energy. Two researchers at UC-San Diego have found that it actually has the opposite effect, however. They discuss their findings in this New York Times editorial. While daylight savings does reduce the need for lights in the evening, it also increases the need for heating (in late Fall or early Spring) or cooling (in the Summer) in the morning. Hence, the overall energy consumption increases.
Daylight savings has long been an annoyance to cow farmers (from what I hear) and parents of young children (from what I've personally experienced), who have difficulty readjusting their schedules twice a year. Now that we know daylight savings has the opposite of the intended effect, Congress should do away with it and reduce our energy consumption.