Either way, being able to physically flip the switch to cut off all those game consoles and those sound systems and those cell phone/laptop/whatever chargers, etc. etc. really helps.
I even installed a timer switch on my water heater (until I can get around to replacing the thing with a tankless instead). I found that the long-cycle heating up of the water when it's turned on via the timer, actually uses less power than "maintaining" the heat throughout the day. Though that certainly depends on your usage, of course. I'm a single person and generally only need it powered for a shower. The water remains hot enough even in the unpowered tank throughout the day for things like hand washing. I was surprised what a difference it made. Most of us Slashdot types probably already have programmable thermostats for HVAC, but you don't really think about your water heater sitting there sucking up power all day maintaining hot water you're not using.
I even have my damn dishwasher on a switch, conveniently right next to the garbage disposal switch. Only gets turned on when I need it. Sure, all this was a pretty fair amount of work at first, but once I'd done it, I literally cut my power bill in half. No joke, no exaggeration. Though again keep in mind I'm a single person and don't generally use a lot of power to begin with, admittedly, but still, slicing my usage in half just by putting crap I wasn't using on switched outlets made a tremendous difference to me. And I really don't think it's inconvenient to go over to the entertainment center and, say, flip the Playstation switch when I want to play that.
And as an added bonus, an unpowered device is one less possible source of circuit failure and fire hazard. That's just a nice little icing on the lower-power-bill cake.