Yea, I kind of discovered this effect on my own a week ago, went through some of my favorite flickr entries and redid them...
I used the "Shadow/Highlight" tool under adjustments and a high-pass sharpening layer.
Flickr Link 1 Flickr Link 2
Those flickr links have links down the bottom you may want to click to compare the "before and after".
e: Although I would say he also juiced his saturation up.