For anyone doing 3D work, who sometimes needs Displacement, Normal, Specular, or Ambient Occlusion Maps; I highly recommend picking up ShaderMap Pro.

It costs less than 15 € (< $20 U.S.) and makes the creating (and fine-tuning!) of these types of maps much, much easier. The interface and settings are intuitive and easy to use and it comes with a nice 3D preview mode so that you can see what you're doing to your "object" as you change its respective maps.

Below are two images of a simple cylinder...the first one is without ShaderMap Pro's Maps and the second one is with...

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Here's a couple more without/with ShaderMap Pro's maps:

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Using Gare's Seamless Tile (from another thread)

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Take care

James

P.S. Virtually all 3D packages allow the usage of these maps, they're not Blender-specific.