Fix for headphone jack not working
For anyone who has come across an issue where plugging their headphones into their moto x and then the audio either stuttering between the headphones and the phone's speaker, or just not playing through the headphones at all. The issue is a small metal clip at the top of the inside of the jack. It gets worn away and pushed back and stops making contact with the rings on the jack. Here is how to fix that using a small piece of cardboard or other non-conductive material:
Hope this helps for anyone desperately trying to figure out how to save their trusty moto x.
The link above no longer works, so I posted a photo illustrating where to insert the spacer: http://imgur.com/a/3bHEc