The latest buzz: more jolts Caffeine: It's always been in colas and coffee, but now, even water carries a rush to willing consumers.

The drug is consumed daily on elementary school campuses. It's hidden in candy bars and even in headache medicines.

It's for sale -- cheap -- in all 50 states.

And many manufacturers are rushing to lace their beverages with the stimulant.

"There's no question, Americans have come back to caffeine. It is a trend with a capital T," says Tom Pirko, president of the New York-based Bevmark, a consulting firm to the food-and-beverage industries.

Once found primarily in coffee, caffeine is being pumped into everything from plain water to sweet ice-cream treats. And Americans are eating -- and drinking -- it up.

That's why you'll soon see Surge, the "fully loaded citrus soda" on store shelves next to XTC, which promises "power unlimited."

Or down the aisle from Jolt, "America's Most Powerful Cola," you can find Celestial Seasonings' "Fast Lane Tea" for those days "when your brain's fried but you need to stay in high gear."

"There is no doubt that the consumers today are showing a dramatically increased demand for caffeine-enhanced products and/or products that contain a boost," says C. J. Rapp, president of Global Beverage Co., the producers of Jolt Cola, who announced recently they are adding XTC, a caffeinated power drink, to their beverage lineup.

"Exhaustion is a part of everyone's life, and the desire for exhilaration or a boost is quite natural."

And, so, increasingly, the beverage industry is packaging that boost in a bottle.

Take, for instance, Water Joe, an odor-free, flavor-free, acid-free, carbonation-free blend of artesian water chock full o' caffeine. Conceived by a former Arizona college student who needed help pulling all-nighters, it hit Midwest markets in late 1995 and is today selling 400,000 bottles a week nationwide.

The 16.9-ounce bottles contain 70 milligrams of caffeine, about the same as a five-ounce cup of instant coffee.

"When I was in college, I didn't like the taste of coffee or colas but I needed to stay awake to study," says David Marcheschi, the creator of Water Joe.

And so now his company, the Chicago-based Water Concept, sends a driver from campus to campus extolling the virtues of caffeinated water.

"When it's hot out, the last thing you want is a cup of coffee. You want something cool and refreshing," Marcheschi says.

His idea has caught on.