Almost everyone in the fitness, conditioning, and nutrition field mentions a minimum of 8 glasses of water per day. Most recommend a GALLON a day. Physicians see this as a fad. It may be largely promoted by companies that sell bottled water and water filters. Consumer Labs have tested over and over again that bottled water is NOT better than tap water. I remember when water was free and no one walked around with a constant liter or gallon sized bottle with them.
I can’t imagine how 1950’s laborers and athletes survived without a gallon jug around them for twenty four hours a day.
Try doing a search at www.arthurdevany.com. Plug “water” into the search function to read about the evolutionary reasons for water drinking.

Here is some data from the Urban Myth site, Snopes.–
http://www.snopes.com/medical/myths/8glasses.asp

Maybe they should put free internet in the public bathrooms. Most of you have lots of wasted time there anyway.