The myth of the eight glasses - How much water do we really need?

I was reading the newspapers over the weekend, and I came across this piece of news about water intoxication. A radio station in California held a contest where contestants had to drink lots of water and hold in their pee to win a Nintendo Wii. One of the contestants, a mother of three by the name of Jennifer Strange, died hours after the competition from water intoxication. Besides being a freaky incident, this piece of news caught my attention as I've recently resolved to drink more water. While I don't think I'm in danger of electrolyte imbalance or anything, it just made me think, how much water do we need to drink? Assuming we are drinking water within safe limits, is more water good? How much is safe anyway?

Actually, it looks like drinking more water is a goal set by many. Just look at how many people extol the virtues of drinking more water. From better complexion, increased alertness and loss of weight, it seems that increased water intake can help you do it all. Or can it? According to this, we can probably do fine with about four glasses of water each day. The claim that the average person needs to drink eight glasses of water per day to avoid being chronically dehydrated, according to the website, is just an urban legend. But there are benefits to being well-hydrated.

So, do we really need to drink eight glasses of water a day? I guess we can do fine with less, but there's really no harm in that volume of water, unless you have some special condition. So I'm sticking to my resolution and see if the benefits really are that many :-)