Virtually anyone who's been a frequent smartphone user for the past few years has already suspected it, but O2 UK has provided some possible evidence in a study: calling is one of the last things we do these days. Although the number hasn't gone down, the 12.1 minutes of time study subjects spend talking every day is just fifth-highest on the list of what they do with their smartphones. Web browsing (24.8 minutes) and social networking (17.5 minutes) dictate the largest slices of time, but the combined effect of all those apps, media playback and messaging leave voice as just 9.5 percent of the 128 minutes of daily use. The British carrier sugg