Sunflower House: fun to play in once the sunflowers grow tall! I have seen this done with on large square with side "rooms" and an entrance area. Fun for kids especially if they plant seeds and tend .making their own playhouses.
Essentially, you affix crayons to the top of a canvas, and blast them with a hair dryer. Watch as the colors bleed down the canvas, creating a beautiful, colorful mess! I can imagine this being a great project to hang in a child's room. This is very cool!