The show-me shower system uses a LED display system to notify you how much water you use during your time in the shower. One LED is lightened up for every five liters of water consumed. Would you want something like this installed to help reduce household water use?
"The prototype also triggered some interesting side effects. A couple used to argue that one of them always took longer in the shower and consequently used more water. After they installed the display, they learned that the woman used only half as much water, even though she spent more time in the shower. This discovery stimulated the man to further reduce his own water consumption."