Standby TVs Waste Electricity, How About ACPI?

twitter asks: "There's power management and there's standby, do you know the difference? The BBC is running story on how much electricity is wasted by TV standby mode. Thanks to the very useful EnergyStar program, I'd be the one in seven who thought they were saving electricity, with the standby button. I've been very happy with APM and hibernation on laptops, and want to do something similar with the desktops I use. What's the state of APM / ACPI Wake-on-LAN for Linux these days?" Slashdot touched on this issue, earlier in the week, but that article was more on TVs, not on computer power saving technologies.