In a series of videos posted to YouTube, engineer Aliaksei Zholner demonstrates a miniscule V8 engine he designed that is built completely from paper (with minor bits of scotch tape to prevent friction).
The engine is so tiny it fits inside the plastic container found inside a Kinder egg. In the the videos Zholner demonstrates the progress of the engine coming together over several months, and the latest clip posted this weekend incorporates a paper throttle that effectively controls the speed of the little whirring device using compressed air.
To demonstrate how the throttle works, Zholner made use of a balloon:
You can also see his wildly popular model v6 engine from last year: