If you're like me - when you are working on an upgrade for a customer you have lots of little notes scattered around. In an ideal world we'd be logged into our computers so that we could make notes in whatever system we're using to track the upgrade.
In reality you generally are jumping from desk to desk and don't always have Internet access.
When you make lots of notes on paper - don't forget that you can make a picture of them with Evernote and sync that image up to your Evernote notebook. Later when you are back in the office you can transcribe any of the notes without worrying you lost the piece(s) of paper you were taking notes on.