Leaving on vacation for a few days or a few weeks?
Think about the environment and your budget before you leave the house. Your house can actually save you money if you unplug all those appliances that say in "ready mode" and suck electricity while you're gone.
Lower the hot water heater temperature to "vacation." Make sure the heater or the air-conditioner is at money saving settings. The house doesn't need to be heated or cooled as much while you're gone.