In the shower I was thinking, "Wouldn't it be cool if I could pause the shower and have it stay the same temperature?* And if while I had it paused—to shampoo my hair or shave or whatever—I could see a holding tank which showed the gallons I was NOT sending down the drain?"
I was picturing a tank in the shower wall with a clear side and an increasing scale of little green leaf icons, something like in the Prius or Nest consumption interfaces. I bet it would actually motivate me to use less water.
Then I realized, actually, I wouldn't need to see a real tank to be motivated. I'd just need a display which represented the water I wasn't using while the shower was paused. These silly little games are truly silly, but they also truly work.
I won't be surprised to find increasing amounts of conservation gamification built into appliances, house fixtures, and tools as the years go by. If it can make mundane things a bit more fun and save resources in the process why on Earth wouldn't we?
*I know this functionality exists, sometimes in quite inexpensive showerheads, but alas, ours does not have it.