The interest in creating what we now know as cell phones started after World War II. The first handheld mobile cell phone was demonstrated by Motorola in 1973 and first commercialr network was launched in Japan by NTT in 1979. (However, fully automated mobile phone system for vehicles existed since the late 50's).
The forst mobile phones were less like what we know today and more like two-way radios that allowed people like taxi drivers and the emergency services to communicate; people who did not need to be professionally on-call at all times saw very little use in them. If you follow thrugh this link, you can see how cell phone subscriptions in the USA have gradually increased: http://www.infoplease.com/ipa/A0933563.html: if you calculate this as percentages of the population you can see less than 0.1% of the US population had a mobile phone in 1985; by 1990 it was 2%, by 1995 12%, by 2000 38%, by 2005 70% and by 2010 97%. The data seems to show that cell phones went into the mainstream from a niche market in the decade between 2000 and 2010.
If you look at this graph http://blogs.sas.com/content/iml/files/2011/08/butterflyplot.png you could see that the group using mobile phones for talking are the 18 to 24, followed closely by those aged 25 to 34, while the under-18 text significantly more than anyone else; overall, the younger you are, the more likely you are to use a mobile phone; which means that the generation most likely to be afected by cell phone use are those of us born in or after the 90's, particularly those of us born after 1995, who are now in the demographic that most extensively uses mobile phones.
The countries with the most mobile phones in use are Panama, Hong Kong and Saudi Arabia: Panama has 202.5 mobile phones in use for 100 persons; that is, over twice as many phones as people.