Electrical timers are humble devices, but they might give you that energy-saving edge you’re after!
In fact, they are one the simplest upgrades you can make to your house. The Intermatic timer pictured here plugs into any electrical socket and switches that device on or off at the times you set. It costs only $11, and will allow you to set two on/off settings per day. You can use them to turn off all those appliances that suck down energy even while idle.
Available from Home Depot and other hardware stores.