Here are the details:
This photo is made with a Pentax K100D and Sigma 10-20mm wideangle lens.
First, I made a HDR ( 3 pictures, 1EV difference). Processed the 3 images in Photomatix.
Then, loaded the HDR-photo in Photoshop. Converted in black & white, Finally, I merged the B/W photo with the color-version. Made adjustments: dodge, burn,... Et voila....the result.