This nifty Canadian device diverts water from your downpipe into any container you like.  Not sure if this is available in Australia, however there's plenty of similar products on the market.  Check out The Garden Water Saver website for details.

According to their website, The Quench shower system can save you massive amounts of water at home by recycling your shower water while you shower.  You can have nice long hot showers without the guilt and only use 4 litres of water. Visit the Quench website for details.

The Chili Pepper saves the water that normally runs down the drain while you are waiting for the water to get hot, saving thousands of liters of water per year.

The Chili Pepper pumps hot water from your water heater to the tap. The initial cool water is circulated back to the cold water inlet of your hot water service. When the water at your tap is at the desired temperature, the Chili Pepper switches off - turn the hot tap and you get nothing but hot water.

Retails for around $470. Find out more at Neco.

Aerator taps add air to the water coming from taps to reduce water use, while still giving a full-bodied flow. They are inexpensive, easy to install (no plumber needed) and help save water in the kitchen and bathroom.

Available at all good hardware stores.