Google just announced that the first Power Meter compatible device that you can buy is available. Pricey (starts at about $200), but I bet things will improve with time.
Obvious DZ callback points:
- For those on load controllers, optimize switch on/switch off time, with a cost of zone hysteresis being a bit higher;
- Long term trend monitoring will allow to spot malfunctioning equipment much faster than it would otherwise be possible (often increased power consumption is the only symptom of impending failure, for equipment is usually out of earshot).