I have to be honest, Ben, I'm hesitant to set up the applets I'd like because consistent and accurate device detection still isn't there yet.
A while back, I brought up an applet that would turn something off (eg the air conditioning) when something else (eg the water heater) came on. This would be helpful in utility districts that charged based on demand, where your peak usage is reflected on your bill.
After reading this post, I went back and looked, and even after having Alex try to make sure my hot water heater model was accurate a couple of weeks ago, I'm still missing about half the instances of it turning on. It's not an overly complicated schedule, really - it's on for ~1hr at 5am and 5pm.
I've since found other, more consistent ways to accomplish this objective. I think it's a great idea on paper, but I need more consistency to feel like I can rely on it.