Portable devices, especially those made by Apple, are increasingly popular with teens in the US who can't have enough gadgets in their lives, it seems.

More than one out of every three teens (37 percent) intends to purchase an iPhone in the next six months says a new survey by market analyst firm Piper Jaffray, while a further 17 percent say they already own an iPhone.

Piper Jaffray’s "Taking Stock With Teens Survey" catalogues a growing trend of Apple-faithful teens - but neglects to mention how many are interested in rival products running Android, BlackBerry or Windows Phone 7 operating systems.

Of the 80 percent of teens who own an MP3 player, 86 percent of them said it was an Apple-branded iPod.

MP3 player ownership has dropped in the last six months, falling from 90 percent in Fall 2010 to 80 percent in Spring 2011. However, the increase in the number of teens reporting they use their cell phone to listen to music (up 3 percent in the same period) may account for some of the difference.

"iTunes has remained the dominant music provider with 95 percent market share among online music services," said Piper Jaffray in the April 6 press release while services such as Napster and Rhapsody account for just one percent each.

Seven out of ten teens buy and download music online instead of heading to a retail store (21 percent) or purchasing physical copies from an online retailer (10 percent).

A surprising 22 percent of kids said they already own a tablet computer while a further 20 percent said they plan on purchasing one in the next six months.

The 21st edition of Piper Jaffray’s semi-annual "Taking Stock With Teens Survey" gathered input from around 4,500 students in the US with an average age of 16.5 years.