Found a fascinating publication "Wireless Works" by BBDO and Proximity, from April of 2006. But inspite of it being over a year old, it has fascinating data. They interviewed 3,000 people around the world, and snippets of their findings include:
81% of youth aged 15 - 20 sleep with their mobile phone turned on.
Women in Japan have daytime and evening phones just like they have daytime and evening handbags.
96% of people screen their incoming calls.
76% of Australians and 76% of Spanish have already responded to mobile marketing campaigns, ie interacted with a brand via mobile.
In China if forced to choose between retrieving a forgotten wallet or retrieving a forgotten phone, 69% will go get the phone rather than the wallet.
And 63% of the phone owners will not lend the phone to anyone else.
Fascinating reading. I don't know if the findings are also available in electronic form, but the printed results were a great read. I'll be quoting a few of those statistics in my upcoming presentations from South Africa to South Korea to San Francisco.