Using Phones and Avoiding Laptops at Work

I was surprised to hear that Twitter's and Square's CEO, Jack Dorsey, runs both of his companies using his iPhone only. He says that it simplifies his life and helps him avoid the distractions that would come at him if he were using a laptop instead. He uses Notes for writing all sorts of reminders, tasks, ideas and even emails (he screenshots his notes and sends them to his employees).

He brings up great arguments about the unnecessary diversion of attention, but it's hard to believe you can avoid using your computer in any other corporate position. Even if you could, you'd think it would be way more efficient to be using one.