Bicycle-powered machines

We've only just heard of this project sponsored by Google and Specialized bicycles. Sadly it's now too late to enter for this year, but making pedal-powered contraptions was still a genius idea. There are videos of dozens of entries; our particular favourites include the bicycle tennis server, the elegantly-simple but perhaps mildly pointless pedal hacksaw, the amphibious bike-yak (though – hang on a minute – why doesn't it sink again?), and the bicycle water distiller, which must be darned hard work.