The useless machine is a simple box with a switch and motor, when you turn on the switch the lid opens and the arm swings out and turns off the machine and then retracts. It is so simple but brings a smile to the face of everyone that tries! The Useless Machine was not created by me, it can be found in Make Magazine and in numerous Instructables and DIY articles online.
I have been wanting to make one of these for years since I first saw one in a YouTube video. I am happy to finally finish this project, it took a couple of hours to build.
Here is a detailed video showing the entire build and even printing the arm that turns the switch off.
Here is a link to some Make and Make Magazine posts:
http://makeprojects.com/Project/The+Most+Useless+Machine/91/1
http://makezine.com/23/uselessmachine/
A whole bunch more useless machines!
http://hackaday.com/?s=useless+machine
Here is a helpful site that has a schematic for how to wire the device.
http://9x20lathe.blogspot.com/2010/01/components-and-schematic-for-useless.html