Yes. I work for an environmental organization nd we recommend that people unplug their appliances when not in use. Appliances continue to suck energy even when they are off. For example, if you leave your cellphone charger plugged in when it is not charging your phone, it is still apparently using trace amounts of energy. The bigger offenders are the appliances that have a digital display (i.e. the clock on your microwave) because that is using energy to display the time, light, etc. I can't say you'll see a substantial difference in your energy bill, but it just takes a minute to unplug everything and it does make a small difference if you're out of town for 7 weeks. The most important thing is to turn off your air conditioner since that uses a ton of energy and you won't need it if you're gone. For the future, an easy way to do this is to plug appliances, computer, etc, into a power strip and then you can simply switch off the power strip when not in use, without having to unplug and replug everything.