comScore (http://www.comscore.com), which measures the digital world, released data from the latest comScore MobiLens service, reporting key trends in the U.S. mobile phone industry during the three month period between November 2009 and February 2010.

The report ranked the leading mobile original equipment manufacturers (OEMs) and smartphone platforms in the U.S. according to their share of usage by current mobile subscribers age 13 and older, and reviewed the most popular activities and content accessed via the subscriber’s primary mobile phone. The February report found Motorola to be the top handset manufacturer overall with 22.3% market share, while RIM led among smartphone platforms with 42.1% market share.

Approximately 45.4 million people in the U.S. owned smartphones in an average month during the December to February period, up 21% from the three months ending November 2009, according to comScore. RIM was the leading mobile smartphone platform in the U.S. with 42.1% share of U.S. smartphone subscribers, rising 1.3 percentage points versus the prior period.

Apple ranked second with 25.4% share (down slightly from 25.5% in November), followed by Microsoft at 15.1%, Google at 9.0 % (up 5.2 percentage points), and Palm at 5.4 %. Google’s Android platform continues to see rapid gains in market share as more Android-compatible devices are introduced to the market.

In an average month during the December through February 2010 time period, 64% of U.S. mobile subscribers used text messaging on their mobile device, up 1.9% points versus three months prior. Browsers were used by 29.4% of U.S. mobile subscribers (up 2.4 percentage points), while subscribers who used downloaded applications made up 27.5% (up 1.8 percentage points). Access of social networking sites or blogs continued to grow, increasing 2.9 percentage points to 18% of mobile subscribers.