Since I seem to be on an aircraft several times a week, I’ve actually rediscovered my spiral notebook as a therapeutic way to continue my work-obsessed day. Brainstorming, the omni-present To-Do lists, and diagramming my next killer app all lend themselves well to paper - all of which has been stated in various ways above. The difference here is that I don’t have a choice. There’s a magical time between “The cabin door is now closed” and “You may now use personal electronic devices” where an avalanche of ideas flow to my brain and need capturing. Paper is the only thing currently sanctioned by the FAA. Works for me.