Sometimes I'm not the smartest investor -- like right now. As a shareholder of both PepsiCo (NYSE:PEP) and Coca-Cola (NYSE:KO), I'm about to advocate something that would hurt their businesses: Stop drinking bottled water!

OK, that might be a bit extreme, but consider cutting back on it considerably. Here's why:

  • Although it's become very big business, with annual sales topping $11 billion, much of what we buy in plastic bottles, thinking it's special and pure and natural, is really just modified tap water. Coca-Cola's Dasani, for example, is just that -- water from municipal systems that has undergone special filtration to make it taste better.
  • You can save a lot of money by sticking to tap water, if your local water tastes good. Try a blind taste test and see for yourself. If you're paying $1 per serving of bottled water twice a day, that amounts to some $700 per year. You might spend just $25 or $50 on a water filter system for your home instead and pocket the difference, which you can invest.

If you can't
If you just can't cut back on your bottled water consumption because you really don't like the taste of your tap water or don't feel that it's safe to ingest loads of chlorine, all is not lost. Drinking water, after all, is better than drinking soda, and that's (to a great degree) what's behind the surge in bottled water sales: a drop-off in soda consumption. David Lazarus recently reported in the San Francisco Chronicle that according to some experts, bottled water could overtake soda as the leading beverage in the United States within a decade. He explained, "The average American consumed almost 28 gallons of Dasani, Aquafina, Evian or hundreds of other brands [of bottled water] -- more than any other commercial beverage except soda. More than milk. More than coffee. More than beer."

So bask in the health benefits of drinking water (though your tap water, again, is likely to offer exactly the same benefits, for nearly no money).

Another option is to consider making money off this bottled water trend. You can do so by investing in purveyors such as Coca-Cola, PepsiCo, Nestle, and Groupe DANONE (NYSE:DA).

Meanwhile, examine other aspects of your spending life to see where you might be able to painlessly save a lot of moola. For more money-saving information, tips on great deals, and general investing guidance, take advantage of a free trial of our new Motley Fool Green Light newsletter service. I think you'll like what you see.

Longtime Fool contributor Selena Maranjian owns shares of PepsiCo and Coca-Cola. Coca-Cola is an Inside Value recommendation. The Motley Fool has a full disclosure policy.