My little guy has a couple of sets of flash cards bought at the dollar store. There is a set for insects, one for astronomical objects, one for states of the union, etc. Each pack cost a buck, and each card gives information on boll weevils, the Milky Way, Vermont, etc. Good useful information. When I cache by myself, I sign the log and be on my way. When my son (he's 4) goes with me and finds something he might want to keep, he leaves one of these info cards. I figured they might be of interest to the type of kid that would go caching.
Yeah? Sound good?