Red Bull

PRODUCT A highly caffeinated energy drink that doubles as a mixer

HOW IT STARTED Popular with athletes in Austria, its country of origin, before it hit clubs in the U.S.

JUDGMENT CALL Cool, we think. After a few mixers, it's hard to tell

The Austrian beverage Red Bull stands out in an oversaturated market by leading a double life: energy drink by day, mixer by night. Red Bull, which retails for $1.99 a can, sponsors such varied sporting events as street luge and Formula One racing, but its core constituency is fast becoming clubgoers, not athletes. The sugary yellowish brew, first introduced in California in 1997 and now available in more than 20 states, has hit the club circuit at such hip spots as Sky Bar in Los Angeles and Twilo in New York City. Leonardo DiCaprio served Red Bull at his millennium bash, and, according to the company, Demi Moore orders cases of the drink that promises to "give you wings."

Among the active ingredients in the concoction are the amino acid taurine, vitamin B12, sugar and a jolt of caffeine (each 250-ml can has about as much caffeine as a shot of espresso). For added punch, party regulars prefer their Red Bull with vodka or champagne. "It gives you a high, especially when mixed with other substances," says Lauren, 27, a New York City art dealer. "It lets you party all night long." Best of all, it's legal.

--By Carole Buia