A do-it-yourself s'mores kit is a surefire way to turn a homesick grandchild into a happy camper: Pack graham crackers, marshmallows, and a few megabars of chocolate, and your youngster will instantly be the coolest kid in the cabin. Shadow puppets make scary nights fun, and a book like The Art of Hand Shadows
(Dover, 2002) can show a young puppeteer the tricks of the trade. (Pack it with a sturdy flashlight — a useful camp tool in its own right — and spare batteries.) And Summer Camp Mad-Libs
(Price Stern Sloan, 2005) are always fun after lights out. Cool PJs, a jump rope, a deck of cards, or water balloons could round out your package. You can even include some pre-stamped postcards so the kids can correspond with you during the long weeks away.