• by Mark Walsh  @markfwal, November 4, 2011

Android continued to gobble up an ever-larger share of the U.S. smartphone market in the third quarter. For the three months ending in September, the Google mobile platform powered on average nearly 45% of U.S. smartphones -- up 4.6 percentage points from June, according to comScore. Other mobile operating systems were either roughly flat or lost share during the period.

Apple's iOS, for instance, gained just 0.8 points to reach 27.4% share, followed by BlackBerry-maker Research in Motion, which dropped 4.6 points to 18.9%. Rounding out the top five, Microsoft and Symbian were both down slightly from June, at 5.6% and 1.8% share, respectively.

On the manufacturing side, there was little change in the last three months in the ranking and share of the top five phone makers in the U.S. Samsung was again the top player, with an unchanged 25.3% share, followed by LG, at 20.6%, and Motorola, at 13.8%. Apple was the big gainer in the bunch, up 1.3% to 10.2%, while RIM slipped 0.8 points to 7.1%.

Data released by research firm IDC Thursday showed that Samsung had surged past Apple in the third quarter to become the top smartphone maker worldwide, with 20% share and 23.6 million units shipped.

When it comes to mobile content use, the comScore data showed that people downloading apps was the fastest-growing activity, increasing three percentage points to 42.5% in the quarter. That was closely followed by the proportion of those who used a mobile browser, up 2.4 points to 42.9%. Nearly a third (31.5%) of mobile users accessed a social networking site or blog on their phones, up 2.4 points; 28.8% played a mobile game (up 1.9 points); and 20.9% listened to music via mobile, up from 19% in June.

A separate study from the Pew Research Center this week found that 38% of U.S. adult mobile users downloaded an app in August, up from 22% inSeptember 2009. Text messaging remained easily the most pervasive mobile activity, with 71% texting as of September, according to comScore.