Tonight I saw an Instructables project called Augmented Water. I'm not sure why they called it 'augmented,' although it might be intended to mean the water faucet has something extra added to it (in this case to encourage using less water). This project adds to a water faucet an extension
consisting mainly of a flowmeter, an Arduino and a strip of LEDs (light emitting diodes).
The concept is to visually let the person who opens the faucet know when they've used a certain amount of water, with the expectation that the LEDs lighting up or changing color will prompt the person to close the faucet more quickly than if they didn't realize how much water they were using. According to the Instructables article, the code is written to turn the LEDs red after one liter is used.
In the comments on the project webpage, one reader suggests using "an ATiny85 or an Arduino micro to shrinkify things." The project post author replied by saying, "I'd love to see an energy harvesting mod, e.g. inside an LED shower head."
One hack I think would be cool is along the lines of what the post author suggested. I'm not sure what they mean by "an LED shower head," but it would be interesting to modify or create a shower head that had LEDs that generated soothing 'happy' light when it starts running, but after a certain flow the LEDs start giving off a less happy light to encourage you to end your shower shortly. If you don't shut the water off after a second usage level that you've programmed in, the LEDs are changed so they give off downright annoying and unpleasant light. (Now I have to Google to see if someone already sells a shower head like that.)
What are your hacks for this? Who knows -- if you come up with some good ideas, maybe people will want to buy them from you, or you might have an Instructables post written about the hack you've built. Bring both your ideas and any physical models you build to the June 26 meeting or email the ideas or pictures to me (arcatabob [att] gmail [dot] com) if you're not going to be at the meeting.