Piano Staircase

For comments from the other times this was posted:<p><a href="http://news.ycombinator.com/item?id=872759" rel="nofollow">http://news.ycombinator.com/item?id=872759</a><p><a href="http://news.ycombinator.com/item?id=873059" rel="nofollow">http://news.ycombinator.com/item?id=873059</a><p><a href="http://news.ycombinator.com/item?id=871721" rel="nofollow">http://news.ycombinator.com/item?id=871721</a>

A simple yet brilliant idea, but my worry is, Will adults let kids play on that staircase? :)