Hack your commute: Digitise your paper documents

Are you someone who prefers making handwritten notes to smartphone memos? Someone who believes the best way to read something with due consideration is to have it printed out so you can make notes in the margins? Someone who needs to make mark-ups on proofs on a regular basis?
If so, on more than one occasion you have probably found yourself sitting on a train frustrated at the realisation that your most important piece of work only exists in hard copy, and you don’t have it with you. If