CrazyBump is simple, easy-to-use yet professional 2D photo-to-3D map generation application. It doesn't offer many adjustable parameters, but still has a lot more details than the functionally similar Photoshop plugins, and is much easier to operate. Plus, it supports exporting normals, displacement, occlusion, specularity, and diffuse these five types of maps at the same time (i.e.: importing one image will result in five effects of maps simultaneously), as well as real-time preview.