It’s as if the two just-released studies – from Nielsen and the Pew Internet Project – about US smartphone use were timed to Apple’s unveiling of the iPhone 5 (a quick list of what’s new about it at the New York Times) this week. Nielsen says that, not only do most of US cellphone owners use smartphones, but now the majority of teen cellphone owners in the US have them – a higher percentage of them than for cellphone owners overall, in fact. According to Nielsen’s latest figures (July) – cited by TechCrunch – overall, 55.5% of cellphone owners’ devices are smartphones, up more than 5 percentage points in May. Though not the largest, 13-to-17-year-olds are the fastest-growing smartphone user category, up more than 20 percentage points over the past year from 36% to 58%, Nielsen found. The Pew Internet Project didn’t survey teens, and its numbers were for US adults, not US adults who own cellphones. The Pew researchers found that 45% of US adults own smartphones, 34% own feature phones (just talking and texting), 5% told Pew they do not know if they have a smartphone or not, and 15% have no cell phone at all. In an effort to explain the fast pace of growth among teens, said that “recently launched shared family data plans have made the price sensitivity surrounding smartphone monthly bills easier for families to handle, even in a down economy,” TechCrunch reported. It says the biggest smartphone-owning category is 18-to-25-year-olds, 74% (up a mere 15% from the previous year) of whom own these phones that go beyond texting and talking to do just about everything that a laptop does. [Meanwhile, the Los Angeles Times reported that Nielsen also found TV-viewing down on TV sets but up on other devices.” Amazingly, “The average TV viewer spent 4 hours, 38 minutes a day watching TV, a decrease of six minutes from the same period a year ago.” But viewing is actually growing by diversifying, as viewers watch TV on tablets and smartphones as well, Nielsen found.