There is research which found that workers distracted by emails and phone calls suffer from various problems such as lower IQ, reduced sleep time, including negative effects on the physical release of stress hormones and adrenaline. Another study found that people who multitasking actually become less efficient at work.
For Q4 2010, the IDC Worldwide Quarterly Mobile Phone Tracker puts smartphone sales at 100.9 million, up some 87% over Q4 2009. They report total smartphone sales for 2010 as 302.6 million, up around 74% on 2009.
The Coda Research Consultancy predict global smartphone sales of some 2.5 billion over the 2010-2015 period, and also suggest that mobile Internet use via smartphones will increase 50 fold by the end of that period.
Morgan Stanley Research estimates sales of smartphones will exceed those of PCs in 2012.
Gartner expect over 500 million smartphones to sell in 2012.
Mark Brownlow. (2010). smat phone statistics and market share. Available: http://www.email-marketing-reports.com/wireless-mobile/smartphone-statistics.htm. Last accessed 29th march 2010.