Here is an article from the Guardian which places an intriguing slant on phone use - titled 'Women use mobiles to deter chat-ups':
"Men, take the hint. When a woman clamps a mobile phone to her ear, or sits ostentatiously typing a text at a bar, chances are that the real message is intended for you: stay away.
Women are now using the mobile phone as a barrier signal, or 'personal bodyguard', to deter overly keen men from trying a chat-up line, according to a major study of the way the mobile phone is changing the way we interact.
They might even pretend to have a conversation, when in fact there is no one on the other end, as a strategy to keep predatory males at bay, says Kate Fox, co-director of the Social Issues Research Centre, who wrote the foreword to the report, Mobile Life."