Look what I have found

. It is a product that makes the wild claim "Even teenagers can be trained to shower in a few minutes!"

This little gem is not only a shower timer but also turns the water off after a set time. Here is the blurb about it:
The shower is terminated after a pre-determined time and that is followed by a "discouraging" waiting period during which the shower will not operate.
The shower and waiting time are pre programmed by the owner from 0-12 mins.
The unit is located within the shower area at around eye level for audible and visual efficiency.
There is a visual display which counts down the minutes and seconds remaining.
The visual display is supported by an audible beeper.
Is this not brilliant?

But it gets better.
The unit can be retro fitted to a domestic shower. It doesn't require a plumber or even an electrician to install it. You simply use the power point in your ceiling for your exhaust fan.
And the cost - $200

.
I was telling Mr18. He has threatened to disconnect my internet if I install it

.
So what so you think? You can purchase it
here.