This company specializes in hidden passageways for your home or business I suppose. You can pay to have them installed or do it yourself. Click on Videos to see animation of the designs. The
My favorite is the chair that is also the secret entrance to a spiral slide. ( Click on Animation #4) The little kids would be using this one all of the time. "Excuse me I have to go downstairs to get something again"
They claim it increases the value of your home. Of course, it will create buzz in the neighborhood, too.