Several days ago we bought a new toy for our 15 months old son. It's a drawing toy called "Aqua Doodle" and has a magic canvas: when the water filled pen touches the canvas it becomes visible and gradually disappears again within the next few minutes.
Image: the canvas and the water filled pen.
This is great tool for kids... but only for kids? I think this could also be used for presentations, moderation, creative group work, and unfocused people: there's a few minutes timebox to come to the point and sell your idea, nothing more.
Images: disappearing illustration.
The images were shot with three minutes gaps.
What's the big advantage? People need discipline and focus to reach their conclusion within the given timebox. And it should be an entertaining experience for the audience.
There's only one disadvantage: if you're really good at presenting quickly, the time until things disappear might be too long, so you'd better bring a hair-dryer.