A super smart gadget has been designed to save our water and actually make something good out of those dull rainy days. It's called RainDrops by Evan.
This product is designed for collecting rainwater from your roof. You just modify the existing gutter system. The rainwater will store in many standard plastic bottles, you can use it water your garden or washing your hands!
The RainDrops system simply allows people to adapt standard plastic bottles to an existing gutter system to collect rainwater. Read more about it here