They're a fashion accessory and a leisure fad, but mobile phones are also a kind of "security blanket" for adolescent women according to researchers at the University of Technology, Sydney.

In a study of the way young women use mobiles Dr Stephen Wearing and Dr Carmel Foley from the School of Leisure, Sport and Tourism in the UTS Faculty of Business have found that young women feel safer and more confident in public with their phone.

In interviews teenagers told the researchers that they didn't feel as intimidated being on their own on public transport or in public spaces if they could quickly get in touch with a friend.

"When we started the study I had a fairly negative view of the consumer culture side of mobile phone use among young women, but as we talked to them it became clear that there was a lot more to it than fashion and peer pressure," Dr Wearing said.

"The phone suggests 'I have friends', so in a public space offers an image of confidence and some claim to autonomy.

"One of the girls interviewed told a story of a friend shopping in the menswear section of a department store for a pair of boxer shorts for her boyfriend who got over her embarrassment by phoning a friend while she completed the purchase.

"We also have anecdotal evidence that the mobile fad may be supplanting smoking in this age group, but a new study will be needed to test this."