Based on the inspiration from stack-a-pots design to build a column garden, I think of extrapolating this idea further and stack pots to make a self-supporting wall instead.

I have done some sketches, but I don't believe I'll ever have the money, equipment, raw materials and expertise to use the equipment either. So, I decided to look for something equivalent on the market.

I'm looking for a structure made of identical pot modules that can fill any vertical area just like bricks do, be able to support itself well enough to get high, and [if leaning to a wall] should allow drainage away from the wall (Pots having drainage holes on the visible side rather than the leaning side, for instance). It is important tht the modules should have a horizontal soil surface to allow sowing as well.

I have seen this one

http://www.thisnext.com/item/A6838911/22348A66/Mediterranean-Style-Wall

but it is not promissing in terms of available sizes and sturdiness.