Walked outside to check out the street right after EarthHour started. The college student-infested apartment building across the street was mostly dark. Received some dirty looks from folks on the second floor while I was basking in incandescent light from the porch light.
Then I got to wondering if there was a website to monitor energy usage in real time.
Sure is.
It's constantly updating, so you won't be able to see the power spike that happened during EarthHour after tonight. But I've got a screenshot!

Note the time for the power spike. Peaks right at 8:00pm, and slowly ramps down. It's 10:15pm right now and it's still higher than that day-long energy usage plateau.
Heh.