Maybe I should rephrase that to washing your hands on the toilet? Above?
Anyhoo, a colleague picked up one of these interesting toilets recently - a Profile 5 Toilet Suite with Integrated Hand Basin from Caroma (Australia). It's Australia's first 5 star rated toilet suite.
This Caroma model incorporates an integrated dual-flush push button and spout combination designed to lower total bathroom water usage. It uses 4.5 or 3 litres of water a flush - that's around a gallon for the full flush, 2/3 of a gallon for the low flush. Additionally, the hand basin on top of the cistern supplements the water supply for the toilet.
Another great aspect of the toilet is it uses standard fittings, so no special plumbing is required. I don't think this Caroma model is available in the USA; but I believe I've seen similar toilet suites being sold over there, so if it's something you're interested in; consult with your local bathroom/plumbing supplies store.
When you think about how many times we flush the toilet a day and the associated hand washing, it comes to a lot. In fact, up to 30% of a household's water use is just toilet related. All that drinking water going literally straight down the drain.
In a world where potable water is so scarce in many places and the amount of resources and energy required to get fresh water to our homes, we really need to rethink our toilet habits - and this toilet suite looks to be a step in the right direction.
Related:
Humanure - composting human wasteSimple water saving tipsCalculate our water footprintSewage wastewater treatment 
