This little pocket mystery has been bugging me for a while but I completely forgot about it until today. Apparently, this pocket was designed in 1873 by Levi Strauss (the guy that started the Levi denim line). This mini pocket was originally made for pocket watches protection for cowboys when they rode on horses because wearing it around their neck will get them easily tangled up.
However, this ingenious ideas was impractical because it would take too much effort to take the pocket watch out. Thus, the mini pocket got smaller as time passed. Even though pocket watch fell out of favor the mini pocket stayed with the classic denim design because it was useful for other things like resting your thumbs or a random small objects. I've seen people keeping their ipod shuffle and usb intact during commute with the mini pocket.
Did you ever use the mini pocket?