There is a very nice junkbox farmspot in Uldum. I couldnt find any post about it (apart from this being a farming spot which I found pretty hard), so here goes:
There is one quest in Uldum that requires you to bomb an area (Fire From the Sky - Quest - World of Warcraft) to kill 100 infantryman. These infantryman can also be pick pocket though. They walk in packs of 10 with one elite. If you go pickpocket from all the way down coordinates 41.4 - 12/3) to all the way up (36.3 - 15.4) you can go back down and start over without killing them.
I got between 3 and 5 junkboxes per run.
Happy hunting!
ps. My first post, hope I am not violating any rules.