Adding to the topic of water frmo a few days ago:

Drinking Too Much Water Can Kill You: "A new review of three deaths of US military recruits highlights the dangers of drinking too much water." [From the Desktop of Dane Carlson]

Water toxicity is quite scary. I read an article recently that was talking about marathon runners who had the same problem. In one case the woman didn't have any issues until after she'd already gone home after the race.