Market researcher ComScore has Apple Corp closing in on market leaders Motorola and Research In Motion, as mobile texting and social networking gain in popularity.

ComScore's latest data from the last quarter of 2009  (September through December) puts cell phone vendor Motorola in first place  in the U.S. with 23.5% market share, followed by LG, Samsung, and Nokia, with 21.9%, 21.2%, and 9.2% market share, respectively.

Samsung had the strongest increase with 0.8 percent growth over the period, and Motorola’s numbers actually declined 1.4% during the period.

RIM continues to dominate the smartphone market, with 41.6% market share, though the Waterloo, ON-headquartered company’s its share declined by about 1%.

Apple is a distant, but closing, 25.3 percent of the smartphone space, picking up 1.2% market share over the period.

Apple was followed by Microsoft, Palm, and Google, which held 18%, 6.1%, and 5.2% market share, respectively.

Google saw the biggest gains of any smartphone OS on the market. It increased its market share by 2.7% during the last quarter.

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ComScore also found that text messaging remains popular. In September, 61% of mobile users text messaged others. By the end of December, 63.1% of all mobile users in the U.S. were text messaging.

According to the researcher, mobile Web browsing, mobile gaming, and use of downloadable apps are growing in popularity too.

ComScore found that 27.5% of U.S. mobile users surf the Web on their phones, while 21.6% of users play games, and 17.8% use downloadable apps.

Social-networking use and music listening are also increasing: 15.9% of mobile users access a social network or blog and 12.1% listen to music on a mobile phone.