Photograph?

This is an awesome photograph. I have to find out how it was made - is it a  digital manipulation? Is it special camera equipment? Is it a specific program stiching it together? This deserves more investigation, as the website I got it off was a blog, and the bibliography link was out of date.

EDIT:
Alright, I found some tutorials. Most of the other types seem to do it the other way - the move the ground into a ball at the center & have the sky around the edge, so that it looks like a small planet.

Anyway, the tutorials:
http://valerie.desnoux.free.fr/pano/pano_en.html
http://forums.finalgear.com/photography-tutorials/tiny-planets-from-panoramic-photos-36628/
http://www.youtube.com