It's been a while but I haven't been completely idle during the holiday season: In this post I am happy to present a small Blender addon that creates walls of irregular stacked stones.
For quite some time Blender users have known the excellent masonry addon but I wanted irregular walls (and a proving ground for serious bmesh programming).
The addon offers a number of controls to tweak the appearance that should be quite self explanatory. It's available from GitHub and discussed in this BlenderNation thread. Download it and select File->User Preferences->Addons->Install from file to install it and it will then be available in the Add->Add mesh menu in the 3D view.
The mesh that is created consists of separate n-gons and the depth is provided by a solidify modifier topped by a bevel modifier. Currently you will have to do the uv-unwrapping yourself. The image at the start was created with a procedural stone texture.