Making phone calls is the 5th most common activity that British smartphone owners do on their phones

"On average, smartphone owners now spend over 2 hours a day using their phones, according to O2’s “All About You” Report into the way customers are using their handsets. However, the research found that making calls comes just fifth in a ranking of things they are used for.
Smartphone users spend more time browsing the internet (25 minutes a day), social networking (17 minutes a day), playing games (13 minutes a day) and listening to music (16 minutes a day) than they do making calls (12 minutes).
How long we spend using our smartphones (by activity) each day:
Activity  Time/day
Browsing the internet  24.81 (minutes)
Checking social networks  17.49
Playing games  14.44
Listening to music  15.64
Making calls  12.13
Checking/writing emails  11.1
Text messaging  10.2
Watching TV/films  9.39
Reading books  9.3
Taking photographs  3.42
Total  128"
Source:  Press release from O2, 29th June 2012
(Click on the link to see the table formatted correctly!)