simple and effective...

Why isn't this thing mandatory in new homes? Or subject to a rebate of some kind?

Image shameslessly stolen from The Age

It's perfect in its simplicity. And absolutely correct in its core assumption that we lazy humans won't make any effort to save water that involves more than a seconds work.

The way this thing works is it allows you to flick off the water in the shower, while you're lathering up or whatever, then turn it back on at the same temperature setting. Rather than all that hassle of resetting the water when you turn it back on, you see.

Ingenious!