Marshmallow Catapult: I thought this would be a fun and great idea for students to make in class. The project of the marshmallow catapult incorporates both art and science.when you can't buy them all a marshmallow gun!
Another version on rain gutter gardening. Want to grow a salad garden but have no room? Try gutters! Affix them to a fence, slope them for drainage, and voila! Of course,for this I'd need a backyard wider than a hallway.