International research firm Jupiter Research is predicting that US MP3 player shipments will top 3.5 million in 2003.

Jupiter also suggests that shipments will continue to grow by 50 per cent a year for the next three years, with 26 million MP3 players reaching the hands of Americans by 2006.

Mass ownership of these devices is likely to "help spur digital-music sales", according to Jupiter, which is good news for Apple, who the report says, has "energized the music industry" with the iPod and iTunes Music Store.

Jupiter also found that nearly 60 per cent of consumers planning to buy a music player will be shopping online this Christmas.

Jupiter Research VP and research director David Card said: "They're not quite this season's DVD player, but portable music players, combined with online music stores and services, will be a strong holiday shopping combination.

"Judging from the survey responses, online retailers should promote factors such as beating the crowds, convenient shipping and competitive pricing to lure these shoppers.

"The survey also showed that these shoppers were less worried about credit card security than average, but more concerned about late arrivals and returns."

The company also expects demand for MP3 players with hard drives to outstrip demand for those with flash memory in 2004.