If you take a soda bottle, fill it with sand and place it inside the flush tank, you can save 1 litre of water everytime you flush...that is almost 750 litres in a year!...
Over here all the local authorities well send you a free 'hippo' on request... a simple thing that can save up to three litres per flush... info here..
Why don't you just go out and buy one of the newest toilets that are energy efficient? You buy those curly bulbs cause their efficient don't you or do you?
the tip is just a suggestion...because this is a forum for all the people in the world..people who may not have the new kind of toilets yet but can still save some water if they want to....
I think the tip is a good one. I wish people would keep in mind that not everyone can afford to just run out and get the get equipment. It takes money, a rare commodity to many of us.