A chindogu is an "unuseless" invention. They tend to focus on functionality to the exclusion of practicality. They work, but no one would ever use them. Just do an image search for "chindogu" and you will find a ton of ridiculous products. So when Instructables hosted a chindogu contest, I had to contribute with something ridiculous of my own. The result was "The Food Magnifier." Check it out.