I have over the last several weeks made myself get into the habit of turning off my computer monitor as well as my computer when I leave work. It's a tiny thing, but it makes a difference. I also set my computer to go to sleep when I leave it alone, something most of us usually have set to stay on all the time. And I'm working my way up towards just unplugging everything when I leave. As of today I pulled my surge protector out so it's easier to get to it to turn it on and off and reduce my overnight load.
It's maybe a little too small of a thing to feel like it's a big difference, but I'm going to try and convince the rest of the organization to try it and then it could really add up. I'd originally intended to do the full day challenge, but it hasn't been logistically feasible for a variety of reasons. So I figure I'll just find the new habits I can establish and substitute those.