I am going to make a machine that once it hears a toilet flush it will yell, "WASH YOUR HANDS!"
This won't just be for the littles, but the adults as well. Yuck. I only have a handful of kids that use my restroom and I have to remind almost all of them to wash, so I can only imagine what goes on (or doesn't) in the other restrooms.
And the the ones that don't flush, maybe a sensor? Once you cross the threshold of the stall it will yell "WASH EM! WASH EM REAL GOOD!" Or something like that.
What about you all? Any inventions you wish we had to make things a little easier, or cleaner?