What to give

Off to Vanuatu next week and looking for suggestions as to suitable gifts. I'd much rather give to schools than to individual kids - but I don't want to be weighed down like a packhorse! People say books and pencils are always welcome but has anyone come up with other clever ideas that have gone done well? (I'm coming from Sydney.) I'm thinking of going to a few islands like Nguna, where a previous poster said it's a good idea to bring village chiefs a gift. But what? A few other people have said food. Australian junk food is probably not wise! What sort of things are in short supply?