The Waterpebble is a little device that monitors the amount of water going down the drain while you shower. After monitoring your first shower and using it as a benchmark, Waterpebble indicates via a series of flashing lights when you should finish showering. With every shower it fractionally reduces the time you're allotted, thereby helping you save water.
Here's how it works: Place in the shower near the plughole. Shower as normal. The lights will flash green, amber and red as Waterpebble memorizes your shower. Then each time you shower, it reduces the amount of time you're allotted fractionally. Waterpebble flashes green to show when to start, amber to signify when you're halfway through, and red when you need to stop.
You can purchase it through Dry Planet for £5.31 (about $8 USD) for one unit.
What do you think? Good idea or just another unnecessary gadget?