Despite Gary's comedy moustache he does make the point that there are actually very few products on the market to help you to save water effectively. In the UK the legislation for water saving is still very weak and the perception of water saving very much takes a back seat to saving energy. There are some basic things you can do to save water:
Chose an "A" rated washing machine
Don't leave the tap running whilst you brush your teeth
Wash your car with a bucket and sponge rather than putting your car through the car wash
Take showers rather than baths
If you live in an area which gets water from a DESALINATION plant, every time you save water -you are also saving a lot of electricity. Desalination plants take sea water and turn this into drinking water. In fact generally speaking, the two things often go hand in hand, saving water, saves electricity... as all water coming through you tap has to be treated to drinking water standard and pumped to your home.