Quite a few people have requested some more information on how to achieve the following effect in your photos. Well, here it is. I should note though, that this doesn't work on all photos (or at least it doesn't look as good as it could). Also the values of radii I have used in this tutorial entirely depend on the size of the image and on the effect you wish to achieve. Less talk, more action...

1. Download the original file here (photo by Aaron Brown). I would suggest using this image for starters, so you could exactly re-create the effect and get the feel for things that need to be done (or be a rebel and use your own image =P).
2. Open it in Photoshop (I am using Adobe Photoshop CS2).
3. Duplicate the layer twice by pressing "Ctrl + J" or by right clicking on the background layer and selecting "Duplicate Layer"

   

4. Select "Layer 1" and press "Ctrl + Shift + U" to desaturate it and "Ctrl + J" to duplicate it (you will now have 4 layers in total, two color and two black and white).

   

5. Set blending mode of "Layer 1 copy 2" to "Overlay".

   

6. Set blending mode of "Layer 1 copy" to "Color".

   

7. Select "Layer 1 copy 2". Go to "Filter > Other > High Pass..." and set your radius to 50 pixels. Press "OK".

   

8. Duplicate "Layer 1" and drag it above "Layer 1 copy 2". Set it's blending mode to "Overlay".

   

9. This is where the process gets kind of repetitive. Go to "Filter > Other > High Pass..." and this time, set your radius to 30 pixels. Press "OK".

   

10. Duplicate "Layer 1" and drag it above "Layer 1 copy 3". Again, set it's blending mode to "Overlay".

    

11. While having "Layer 1 copy 4" selected, select "Filter > Other > High Pass..." and set your radius to 10 pixels. Press "OK".

    

12. Apply "High Pass" filter four more times (while duplicating "Layer 1", moving it above the previously adjusted layer and changing layer blending mode from "Normal" to "Overlay") using 5, 2, 1.5 and 0.5 pixel radius.
13. Flatten your artwork by pressing little round button, right above the "Opacity" slider.

    

14. Bring up "Hue/Saturation" window by pressing "Ctrl + U". Drag the "Saturation" slider to -30 and press "OK".

    

15. Now bring up "Shadow/Highlights" panel by going to "Image > Adjustments > Shadow/Highlights...". Input the following values:

    

16. You are done! Here is the outcome.

Note: Photoshop is a very powerful tool and similar effects can be achieved in many different ways. This might not be the most efficient way but it sure does the trick. You can also play around with "Level" setting on each one of the duplicated layers in order to give your image a more unique look. Thanks for reading.