Re: Why distilled water over bottled water?
Water consists of 2 parts hydrogen and one part oxygen, chemical formula H2O. That's all water is, just that, nothing more and nothing less. Drink that on a fast and you are drinking 100% pure water.
However tap water and bottled water all have things added to that, possibly fluoride, minerals, maybe things from the manufacturing process that shouldn't be there, plus bacteria and so on.
I wouldn't even think of putting "bottled or purified water" in the same sentence, commercial bottled waters are often very impure, and in the UK we have much lower controls over impurities in shop bought bottled water than in standard tap water.
The distillation process consists of boiling or evaporating water, which allows the H2O molecules to become vaporised. This H2O vapour is then collected or condensed, for example by passing it over a cold surface, allowing the H2O to once again take on its liquid form and reform into pure water, minus any impurities that were in the undistilled source. If for example you were distilling salt water, all you would have left of the original liquid would be dried salt crystals. The distilled product would be absolutely pure water.
Distillation also takes place in nature, resulting in clouds and rain, however due to atmospheric pollution the product that falls to earth may contain all sorts of impurities such as sulphur and carbon.
As home distillers are often electric powered, they can be expensive to buy and are arguably a very ecologically unfriendly way of producing distilled water. Thus you could look at
http://www.builditsolar.com/Projects/Water/Water.htm,
the most promising product there I think is the watercone, also seen at
http://www.watercone.com/product.html.
It will be very cheap, and I will be buying one as soon as production starts, hopefully later this year.