It's both wicked and simple, the kind of thing you can't believe no one's thought of before. Check out the Manifold Clock, by designers Shay Carmon and Ben Klinger (collectively known as Studio Ve). The two hands are connected by a piece of Tyvek, drawing a random-but-not-random 3D form that literally changes by the minute. It's best seen in video:
Dig it? They're for sale.