A few weeks ago, we were trying to beat the heat with a big art day. Project after project was started and abandoned. It was too hot to think, too hot to be satisfied, too hot...until snack time and art project combined with a pile of toothpicks and some mini-mallows.
This activity would also work with grapes, blueberries, melon cubes...as long as the snack is slightly firm. Just present the kids (young or old) with a pile of toothpicks* and watch the fun begin.
*remarkably, no one was seriously poked during this activity, though you might want to keep an eye on littles with their sharp little sticks