DENVER (AP) _ What's hot for 1990? Try ''wet'' beer on the rocks, New Age radio, shorter hair on women and longer hair and wider ties on men, says the author of ''The American Forecaster 1990.''

Also hot, says futurist Kim Long, will be the ''smart toilet,'' a Japanese invention that checks a seated person's blood pressure, pulse, urine, temperature and body weight and displays its findings on a built-in monitor.

New Age radio took off so quickly that it is a major trend, said Long.

''It's been called musical wallpaper, at its most disparaging. It's somewhere between jazz and soft rock, and it has the potential to not offend a fairly wide proportion of the population,'' he said.

''Wet'' beer, a heavier brew served on the rocks, will debut in 1990 along with lower-proof liquor, but low-alcohol beer will continue to founder, Long said.

White will be the fashionable color in clothing for women, who will favor shorter hair, he said. Men will grow their hair longer and wear wider ties, the Forecaster predicts.

Long, 40, a Denver free-lance writer who began the Forecaster in 1983, claims an 80 percent accuracy rate. He also predicted a Dukakis presidency and the demise of television's ''Dallas'' and ''Dynasty.''

Long's book sells fewer than 10,000 copies despite all the interest it stirs up in the future.

''A popular phrase some futurists are using is that life has the potential to move forward very rapidly because 80 percent of all the scientists and engineers who have ever lived are alive today,'' said Long.

''The corollary to that is that 80 percent of all the artists, crackpots and loonies who have ever lived are alive today,'' he said.

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FORT LAUDERDALE, Fla. (AP) - An 8-year-old boy stuck a message in a bottle, threw it into the ocean and waited for a response. He got one five years later - from England.

''Hello Tommy,'' wrote 15-year-old Anya Leeds. ''I don't know whether you remember sending your note in a bottle. We just found it on the other side of the Atlantic.''

''We were royally shocked,'' said Tom Mote, of Dania, whose son Tommy put the bottle in the ocean in July 1984. ''I couldn't believe that bottle had been around for five years.''

The bottle was found by 10-year-old Gareth Wildman on a beach in Penzance, on the southwest tip of England. He gave it to Anya, who worked with her friend, Emma Prowse, 14, to reassemble the message.

''The note crumbled to the touch, but we pasted it together,'' Anya said in a telephone interview with the Sun-Sentinel of Fort Lauderdale. ''It was pretty special to see something so old.''

Tommy, who's now 13, has become a pen-pal to the two British girls, his father said.