Text messaging is by far the No. 1 activity of US mobile phone users aged 13 and up, according to the latest figures from comScore. Though talking on the phone isn’t even on the list (presumably all cellphone users do that), comScore’s January figures show that 63.5% of mobile subscribers send text messages. The other mobile activities on the list are “Used browser” (28.6%), “Played games” (21.7%), “Used downloaded apps” (19.8%), “Access social network site or blog” (17.1%), and “Listened to music” (12.8%). Social networking by phone was the biggest growth area between last October and January, at 3.3% growth over the three months.