Earlier this week survey data from the Pew Internet Project argued that 61% of US adult mobile subscribers now own smartphones. Today Nielsen announced agreement with that number:
More than three out of five (61%) mobile subscribers in the U.S. owned a smartphone during the most recent three-month period (March-May 2013), up more than 10 percent since smartphones became the mobile majority in early 2012.
Comscore, for its part, says that the percentage of mobile users with smartphones is slightly less: 58%. Overall we're talking about 140 - 150 million people in the US now with smartphones.
In terms of OS market share, Nielsen reports that Android has 53% of the US smartphone market, while Apple controls 40%.