For kids on the go, snacks must be portable. When the kids are full (or, more likely, too busy to eat), they can stuff the bags into their pockets and save them until they're hungry again.
Place a graham cracker in a plastic baggy, seal it shut and crush the crackers into a fine sand using a large spoon.
Add a few raisins to the bag and have the kids dig for bugs in the sand. Experiment with other tasty critters--dried cranberry "ladybugs," carob chip "ants" and fruit snack "worms."