We all want to conserve energy, right? I mean, seeing the electric bill shrink from month to month isn't bad news for anybody. But what lengths will you go to to save a few joules? For instance, your DVR is a huge power hog. But if you unplug it before a lengthy vacation—the same way you might unplug the TV or turn off the A/C—it's not going to be able to fulfill it's only purpose. Is it practical? Is it worth it?