Ross C has this in his signature.
HeightMap to NormalMap Convertor - <a href="http://www.rosscrooks.pwp.blueyonder.co.uk/height_normal_bb.zip" target="_blank">.bb</a> - <a href="http://www.rosscrooks.pwp.blueyonder.co.uk/height_normal_exe.zip" target="_blank">.exe</a>