When you drain your bathtub or finish washing your clothes, the water goes down the drain and out to the ocean. It might as well water your garden. Instead, you irrigate with water you could use for drinking or cooking. Continuing drought makes that a wasteful alternative. Calls for conservation are creating a market for greywater systems.
Also, electronic locks make keys for car doors unnecessary -- not just for drivers, but also for thieves.
Photo: Greywater garden with supplemental rain water capture system with cistern (Jeremy Levine)