An article  at Cepro.com mentions how lights can do more than illuminate- they can curb energy use, evoke ambiance, and protect the home with a couple of tweaks:

- Use timers

- Set the scene with an astronomical clock

- Replace switches with dimmers that can communicate together

- Use sunlight sensors to determine if natural light is enough before turning lights on

- Use motion sensors to light a pathway at night

- Integrate the lighting to respond to events from the security system

- Use keypads instead of banks of switches or dimmers

- Set scenes for the use of lighting instead of turning individual lights on or off 

- Use occupancy sensors to detect if a room is occupied before turning on lights