Shot as the weather was changing fast. The clouds were coming, the panorama almost started with sun, and finished in a heavy mist. I shot from bottom to top, you can see the exposure change in several places. Nikon D200 + Nikkor 70-200 @ 200mm except for the sky part shot at 70mm + Nodal Ninja 5L: in total 372 images. It took approximately 15 minutes to shoot all the images.
Stitched and blended in Hugin and Enblend. Remapping the images took 1h30 and the remapped images used 7.3GB of disk space; blending took almost 23 hours (1363 minutes)... and required a maximum of 16,364MB of memory, which I don't have.
My trick for this extra large panorama: I did not use Gimp. I adjusted exposure and cropped everything in Hugin.
The final TIFF image is 3.8GB (the JPEG is 469MB) and is 46,160x40,813. The image uploaded to flickr is reduced 10 times, i.e. only 18 megapixels. The decimal comma in the 1.9 above covers an area of approx 9 million pixels in the full size image, similar to the 10 megapixel camera I used for the shots.
You can view the image in full in Gigapan (you can add screenshots of the funny or interesting things you see).