A model of some rooftiles from this refernce : http://mayang.com/textures/Architectural/images/Roofing/corrugated_tiles_4250870.JPG
Model was used to generate a normal map. the image was used to generate a diffuse.
I also used gimps normal map generator to add smaller details into the normal map that i would have otherwise had to have sculpted.
Made with blender 2.60.4
Wow...This is awesome. The one deserves a higher license. I thank you for sharing this. It will come in handy.