Some things are still important enough to print out and tape to your desk. Here's an example from a mission-critical, highly available service in another industry, one that you may have used to attend this event. If someone has to use that Red Phone, everybody at your airport is about to have a Really Bad Day. You might not have time to find, or be able to access, an online document. Time-sensitive details have to be available when and where they are needed. ProTip: tie a flashlight to the binder with the power outage procedures. And check the battery.