There are many reports out there that the water shouldn't be considered potable if stored in such plastic bottles. Something about the chlorine in the water interacting with the plastic in the bottle.

If you have a good purifier, I think there would be no problems. If anything, it makes for good storage of utility water (ie washing).

I was thinking of using that water for cleaning and washing. Not for drinking. Unless i have to.

I keep a lot of water this way...
as for the chlorine issue, I hadn't heard that, but it is interesting.
I have well water, so that isn't an issue, but maybe running it through a household filter such as a brita might help.

As a general rule, we will add 1 tablespoon of bleach per gallon of water for storage.

From http://www.ready.gov/water the below seems to be what you want:

How Should I Store Water?

It is recommended you purchase commercially bottled water, in order to prepare the safest and most reliable emergency water supply. Keep bottled water in its original container and do not open until you need to use it. Observe the expiration or “use by” date. Store in cool, dark place.

Preparing Your Own Containers of Water

It is recommended you purchase food grade water storage containers from surplus or camping supplies stores to use for water storage.

Before filling with water, thoroughly clean the containers with dishwashing soap and water and rinse completely so there is no residual soap.

If you chose to use your own storage containers, choose two-liter plastic soft drink bottles – not plastic jugs or cardboard containers that have had milk or fruit juice in them. Milk protein and fruit sugars cannot be adequately removed from these containers and provide an environment for bacterial growth when water is stored in them. Cardboard containers also leak easily and are not designed for long-term storage of liquids. Also, do not use glass containers, because they can break and are heavy.

Storing Water in Plastic Soda Bottles

Follow these steps for storing water in plastic soda bottles.

Thoroughly clean the bottles with dishwashing soap and water, and rinse completely so there is no residual soap.

Sanitize the bottles by adding a solution of 1 teaspoon of non-scented liquid household chlorine bleach to a quart of water. Mix the sanitizing solution in the bottle so that it touches all surfaces. After sanitizing the bottle, thoroughly rinse out the sanitizing solution with clean water.

Fill the bottle to the top with regular tap water. If the tap water has been commercially treated from a water utility with chlorine, you do not need to add anything else to the water to keep it clean. If the water you are using comes from a well or water source that is not treated with chlorine, add two drops of non-scented liquid household chlorine bleach to the water. Let the water stand for 30 minutes before using.

A slight chlorine odor should be noticeable in the water, if not, add another dose of bleach and allow the water to stand another 15 minutes.

Tightly close the container using the original cap. Be careful not to contaminate the cap by touching the inside of it with your finger. Place a date on the outside of the container so you can know when you filled it. Store in cool, dark place.

Water can also be treated with water purification tablets that can be purchased at most sporting goods stores.

Water that has not been commercially bottled should be replaced every six months.

More information on water treatment is available at RedCross.org.

Thanks for the link, thecrownsown. That was very informative

I've stored water in plastic bottles before and in the long run somehow the taste felts a bit weird.

Now I use glass bottles and to replace the cap I use some clear plastic fasten with rubber band.