If you're looking to save some water this is a simple thing you can easily do yourself with a little courage and money.
Install a dual flush conversion kit into your existing toilets! For as little as $25 and about an hour of your time you can save water with every flush.
For those of you unfamiliar with the dual flush system it's really pretty simple. Flushing liquid waste requires less water than solid waste to do it's job so why not have a simple way to accomplish that each time you flush?
We purchased 2 different kinds. One simply replaces the existing flapper and handle in your toilet. The other, more expensive, requires you to remove the tank and replace the entire flush valve (overflow tube and flapper assembly). You can make adjustments to the amount of water required to flush liquid waste until it flushes toilet paper with ease. A full flush is used for solid waste.
I did some quick calculations with our toilet.
4 gallons = full flush (solid waste)
1.5 gallons = small flush (with dual flush kit installed)
2.5 gallons = saved for liquid waste flush per toilet used.
$0.19 per cubic ft = cost of water (approximate)
912.5 gallons = yearly savings per toilet
$23 = yearly savings per toilet
So in our house we save, conservatively, $46 a year and 1,800 gallons of water each year. Not bad for an hour of my time.
Here are some products: