This upload is made simply to demonstrate a technique I've been working on, and for this I've used the excellent head model from 'simple three point light setup' by Bensimonds. I had been trying to find a way of making photo realistic rocks for a project I've had in mind for a while and nothing really seemed to come up to scratch. I knew that using photographs with texture painting had to come into it, but I needed a something that would deform the mesh, not just influence the normals.
Then I came across this upload, http://www.blendswap.com/blends/materials/rockwall/
and I knew this was the direction I needed to be going in. It then occurred to me that I could take the texture that is produced by the texture paint layer add on, and use it as the displacement modifier texture. I'm pretty happy with the results, and hope that other rock makers here will find this useful. This model is textured for use with the internal renderer.