I use paper when paper is the most efficient for me. I always care a pen and a Moleskine Cahier Pocket for capturing when I don't have any technology options. I also use business card size notes and a Levenger Two Row Note Card Bleacher to capture, organize, and review items on my main desk. The key for me is to just process these into my electronic world as soon as I know they won't be handled during a normal work day.