Water butts collect rain water from places such as your roof or bath. It's a great way of collecting water for you garden.
This sells a wide range of water butts, to suit most needs:
http://www.thewaterbuttshop.co.uk/index.html
You'll need a rainwater diverter:
http://www.greenfingers.com/supersto...&pf_id=DD3607D
This fits to your down pipe from your gutter. It is designed to fit to the side of a water butt, and if fitted at the same height on the down pipe as the water butt, will stop collecting when the wtaer butt is full.
If the down pipe also collects bath and sink water, you may want to collect from above that point to avoid shampoo and soaps getting in the water butt. This will mean that an overflow system will be a good idea, which is a good opportunity to start a senond or third water butt, so you can increase your capacity if you are a heavy user.
Of course you can do it very cheaply, by finding an old container, such as a 205L plastic drum, or IBC which holds 1m3 of water, which many industries use to buy in liquids, and need to dispose of.
If you need a longer hose from your rainwater diverter, they are 1" ribbed pipes, which are available from aquarium shops by the metre. The taps that a water butt come with can also be bought from shops that sell home brew kits.
If you want to collect bath water seperately, the pipe from the waste water drain should fit this device:
Bath water diverter:
http://www.naturalcollection.com/nat...asp?P36=5CXP3V
It works much like a rain water diverter, except it fits to the darin pipe from the bath, and uses a hosepipe.
Currently, B&Q are selling tall water butts that are styled as marble pillers, but are actually large plastic containers. Just the thing for those concerned about appearance.
This is what an IBC looks like:
