This is a small module which can be used to detect earphone button presses. I was aroused by curiousity on how these buttons worked. I hacked around and found, they emit a certain noise like this. So there went my afternoon to detect the clipping part and make the button presses meaningful. It is explained more succintly in my blog post
I originally made it to control VLC player from button presses but the module is of feeble use, as of now. For using this, you must have a way detect the noise, implying you have a machine with a combo jack [mic + headphone combined jack]. Secondly, I have only tried my pair of samsung earphones; I am not sure how the other pairs would work on this. The example.py shows an example on using the module.