My idea is for all ages, and would be for a smaller group of kids. You take them to the nearest orchard and have them pick apples, oranges, pears, whatever! For small kids, it would introduce
them to fruits and show them that healthy doesn't equal yucky! For older kids it would be a test of responsibility, letting them go off and pick the fruits on their own. Either way it would
demonstrate a good lesson, showing them the "fruits of their labor"!