I have to restrain myself from reposting everything that appears on Kiddley, but I couldn't resist this: how to build your own marble run. What's so wonderful about this (or any other homemade toy) is the permission kids have to break it apart and rebuild. There's no "right" way to do it. Let me rephrase that: the "right" way is whatever gets the marble from the top to the bottom…logical consequences in action. Ideal for little scientist minds.
There's more: the satisfaction of transforming a piece of trash into a magical object. How better to teach your kids to view the world creatively than to make a toy together?