For travel or for birthday goody bags, we love this tiny codex-style coloring book from Monster Books. (Though if you have Borrowers in your house, beware: your copy might disappear. Arrietty is bookish, remember.)
Featuring ten teeny drawings of origami critters, this book measures just over an inch tall. And if you love this mini book and want to expand your collection, this could be a super fun DIY project. All you need is some quality sketchpad paper and semi-decent drawing skills.
$2.50 each at Upon a Fold.