Touchscreen mobile phone adoption in the US grew 159% during the past year to 23.8 million users in August 2009, according to a study by comScore. The substantial growth in touchscreen phone adoption outpaced the already strong 63% growth in the adoption of smartphones.

iPhone Devices Dominant

The rate of adoption is being driven in large part by the Apple iPhone family, which owns 32.9% of the touchscreen device market for users 13 years and older. LG Dare follows with 8.7% of market share, LG Voyager with 7.8%, Blackberry Storm with 7.0%, and Palm Treo with 6.5%.

Younger Users Flocking to Touchscreen

Touchscreen devices and smartphones in general are more popular among younger users.

Key findings:

• 38.8% of all mobile subscribers fall between the ages of 13 and 34.

• 51.4% of smartphone users are in that age cohort, as are 57.7% of touchscreen device users.

• 20.6% of touchscreen users fall between the narrow age range of 18-24.

• Less than 5% of smartphone and touchscreen device users are age 65 and older, compared with 13% of the total US mobile audience.