They can be seen on the bus or train, anxiously tapping their mobile to check for email and messages.
Even in the evening and at weekends, the urge to glance at the smartphone can be irresistible. Indeed, many of us sleep with our phone by our bedside.
But research has found that imposing a ban on staff from checking their BlackBerrys, iPhones or any device just one evening a week can lead to improvements in happiness and performance at work.
The study, by Harvard Business School, involved management consultants being banned from monitoring their work after 6pm once a week. Called 'PTO' - predictable time off - the experiment was carried out on 1,400 employees of the Boston Consulting Group over three years.
Professor Leslie Perlow was inspired to carry out the study after she found that 26 per cent of employees out of a sample of 1,600 managers and professionals slept with BlackBerries or iPhones by their bedsides.