As of July 2012, 74 percent of 25-34 year olds in the US own a smartphone, according to research from Nielsen. That number has jumped up from 59 per cent a year earlier.

Overall, 56 per cent of mobile subscribers in the US own smartphones, compared to 41 per cent last year. And teenagers have seen the biggest jump in smartphone adoption over the last year, with a penetration rate of 58 per cent among 13-17 year olds, compared to just 36 per cent in July 2011.

“Among most age groups, smartphones represent the majority of U.S. mobile subscribers, but American teens were the age group adopting smartphones the fastest,” said Nichole Henderson, a Nielsen analyst. “As teens increase in their share of smartphone owners, mobile carriers and manufacturers should consider how to market to this growing group.”

Android is holding onto its majority in the US, and its lead looks set to grow – the OS makes up 52 per cent of all smartphones owned, but 59 per cent of all bought over the last three months.

iOS purchases showed signs of dropping off slightly, with its share of recent purchases (33 per cent) just below its overall share (34 per cent) – but that effect will no doubt be reversed by the release of the iPhone 5.