I used to carry a small notebook (~2″x3″) with an equally small pen and would jokingly refer to it as my non-digital PDA whenever I took it out in front of fellow digerati. I mostly kept track of to-do items, shopping lists, and inspirations, just stuff.
Forward to 2008 and enter PocketMod. Mash up your design, print, fold, cut, fold some more. Instant paper PDA. Nicely done and just enough fun to try out.
Tip of the hat to Peter Duke.