78.5 million people in the U.S. owned smartphones during the three months ending in June 2011, up 8 percent from the preceding three month period. Google Android ranked as the top smartphone platform with 40.1 percent market share, up 5.4 percentage points. Apple strengthened its #2 position with 26.6 percent of the smartphone market, up 1.1 percentage points from the prior reporting period. RIM ranked third with 23.4 percent share, followed by Microsoft (5.8 percent) and Symbian (2.0 percent).
I wonder why comScore looks at smartphone users ages 13 an up; I personally know several who are younger. My unscientific guess: there must be millions in the U.S.