CrazyBump is an excellent tool that generates Normal Map, Displacement Map and Occlusion from photgraph. You may tweak the generated data by tweaking parameters with real-time preview.
The beta version is free in 30 days. The stable version will be not free. This tool deserves to be paid money. Professional game developers look very much to this tool. And, I want to use this at also home, because the tool is easy to use for programers. Please, low price!
I tried it.
Download a picture from Turbo Squid for test.
Start CrazyBump. Click "Open photograph from file".
Umm. I thought that I should select the right shape.
By the way, the normal mapping is one of the standard expression of the next-gen video games. It's impossible to make normal map by hand, so anybody presents a new way how to use normal map with a new tool.
For example, some tool bakes shadow to texture by the normal map(*). This covers the weak point of the normal map expression. It's impossible to do such texture baking by hand.
This movement is the chance for 3D tool vendor. So they will present many new ways with their new products.
(*) This way is not useful for the case which the light-source moves. But, if a game uses light-map, the light-source can not move. So that's not big problem.