This thing uses the intersection of randomly rotated cubes to simulate a stone, and then creates a wall made from those stones using running bond.
The maximum rotation angle changes the shape of the stone, with smaller values being more brick-like, and higher rotation angles looking like you stuffed whatever chipped granite was lying around into a wall. A master random seed saves your arrangement. The base size and mortar dimensions are customizable as well. A "z_compression" variable is used to compensate for higher rotation angles which would otherwise appear to "float" in the mortar.
Edit (1MAR2014): You can now change the number of cubes used to make a block. A new parameter "power" rotates blocks less based on how many blocks are asked for. So you can add facets without getting chips of stone.
-I want to add circular columns to the ends, so that you can string them together in an artistically pleasing way, without gaps.