Evian is no longer the über-cool thing to tote around. These days, super-oxygenated, vitamin-enhanced and caffeine-enriched water is the drink of choice in fitness clubs and delis alike.

It used to be that drinking even plain bottled water was as laughable as selling ice cubes to an Eskimo. But in the past 10 years, the bottled water industry has increased sales by 125 percent.

Even companies like Reebok, Gatorade, Pepsi, and Coca-Cola have jumped on the bandwagon, coming up with enhanced water for people with active lifestyles.

Stephen Kay, vice president of the International Bottled Water Association agrees people are going gaga for fancy water of all types.

"Water does have different tastes and profiles," he said. "People are demanding and looking for water in their diet."

Some say concerns about tap water's purity fuels their desire for bottled water, but other fitness goals have people buying water with something extra.

"A lot of people are afraid of the contamination in the tap water. The chlorine level is high," said Pat Voegler from Long Island, N.Y.

But when it comes to the tennis court, Voegler said: "I like the Gatorade water. I find it gives me a boost."

But some say the ultimate power boost comes from the extra oxygen in H2O.

"It really does enhance your performance," said Michelle Tatum, director of corporate communications for Life 02, a company whose water contains 10 times more oxygen than an average glass.

And Veryfine's Fruit20, which comes in lemon, strawberry, raspberry, and orange passion vanilla, has become New England's second-highest selling water -- behind plain Poland Springs.

When explaining the appeal of flavored water, Veryfine President Sam Rowse said: "It kind of quenches thirst and tempers your appetite. A lot of people tell me it is an easy way for them to get their eight glasses a day."

There are more eccentric flavored waters sweeping across the nation. The popular Glaceau Vitaminwater incorporates flavorful treats with nutritional supplements into drinks like their Defense Lemon Ice, which contains Vitamin C and claims to boost the immune system.

J. Darius Bikoff, inventor of Glaceau Vitaminwater, calls his product, "The synergy of formula, flavor and function."

When asked about the controversial St. John's Wort contained in Glaceau's Stress-B formula, Bikoff said, "For every 10 seconds of questionable press St. John's Wort has been getting, there are hundreds of hours of clinical studies that go back hundreds of years."

But not everyone is buying into it. Julie Walsh, a dietician and spokesperson for the American Dietetic Association, said many brands purport to be something they aren't.

"Most of [the enhanced waters] contain a miniscule amount of nutrients," Walsh said. "If you eat a normal healthy diet, you don't need it."

Walsh added that enhanced water is not what accelerates performance. "All water, due to the fact that dehydration will inhibit your performance, will increase it if it hydrates you."

After stripping away the pristine packaging and multimillion-dollar ad campaigns, many like Walsh feel that bottled water is bogus. But regardless of the questionable health benefits, growing sales show that Americans are turning to exotic water for everything from a jolt of caffeine to a boost of vitamins.