Lego building challenge: Build something that can launch a ping pong ball. This post has two ways to build a Lego catapult. Great for a rainy day! Legos not just for boys :)
How to make a Catapult for Kids This is an easy to make catapult for kids using some craft sticks and rubber bands. It can launch small objects several feet if used correctly. This makes a great addition to a child's fighting scenes between his toys.