Got a life- or environment-saving idea?

I’m sure some of us have ideas that could (possibly) save peoples health, maybe even lives, or our dear earth.
Maybe you have one, but you think it’s a ‘ridiculous’ one or impossible to carry out.
Have you one such idea?
Would you care to share it (assuming you don’t matter that it isn’t gonna make you any money, because it is for a good cause)?

I have one.
Every year again, i am shocked to hear news-items about young children who die of drowning in pools/lakes/oceans (in the Netherlands).
My idea is (if possible) to make use of the mechanism that we find in life-jackets in aeroplanes, you know, the light that starts to shine when it comes in contact with water.
Instead of a light it could raise an alarm?!
That could alarm their parents/caretakers.
Maybe those seconds (the parents running as fast as hell to their child) would just makes the difference between surviving and drowning?!

And yours?