Gadgets are great. Here's a story about one that costs $20 and saves litres of water in the toilet, from today's SMH.
I think of gadgets every now and then, for example I invented the upside-down fridge (with the freezer on the bottom), but I never got credit for it. I guess this is not surprising, since I didn't tell anyone until I saw one.
I have also thought of a device for keeping bushwalkers cool using the water they need to carry on the walk anyway, but I can't be bothered explaining it here. Suffice it to say that it involves tubes and a hat.