A few data points from my own personal experience.
In 1990 I began renting (yes, renting) cell phones for my business for occasional situational needs. These were suitcase-type phones weighing around 20 lbs, not the kind of thing the average person would carry. Pagers were the norm for personal mobile contact.
By 1994, the top management of my company carried cell phones, so I bought my first - an Audiovox, then a Motorola MicroTAC. All still analog, of course. And definitely a prestige thing. Teen use would have been rare except among the wealthy.
In 1997 came the Qualcomm Q Phone, my first digital (CDMA), with basic texting and internet capability. Coverage was spotty, even though San Diego’s infrastructure was better than most, thanks to being the home of Qualcomm and CDMA.
In fact, I think adoption closely tracked the build-out of 2G infrastructure in local areas, and the state of the hodge-podge of the four competing systems: analog, CDMA (Verizon), PCS (Sprint), and GSM (Cingular/ATT).
The Europeans were way ahead of the US in this, thanks to the early adoption of the GSM standard. A memorable moment came in 1998 when I was attending the CeBIT show in Hannover. I was waiting for a stall in the men’s room. And from behind the closed doors of the 20 or so stalls, all you could hear was people talking and phones ringing (the Nokia song!). I’d guess that 90% of attendees had phones, far higher than I’d have expected in the US at that time. And companies like Orange Mobile were really pushing mobile phones as a universal appliance, not just for elites.
By 2000, I remember discussing the phenomenon of texting with my European friends, and the (still mostly European) problem of kids being obsessed with texting. Over here, the phone companies were just beginning to really push texting as the big thing in their TV advertising, targeted partly at kids, and “family plans”, as the business market became saturated.
If I had to pick a pivotal year for the teen cell phone phenom in the US, it would probably be 2000. And the trajectory of subsequent TV advertising reinforced that by focusing heavily on texting, integrated music features, and video. Since then, with the exception of certain aspects of smart phones (e.g. the business focus of Blackberry), my impression is that teen and youth phone use has driven adult patterns, not vice versa. Hook them early, stoke peer pressure, and you have a market for life.
Today I don’t own a cell phone. Early adopter, early un-adopter. I’m way ahead of the curve. 