Mmmmm....fisheye. Love 'em. I have a 15mm full-frame Sigma fisheye that I use frequently.
I absolutely love the first shot. Very nicely done. What camera did you shoot that with? If digital, what's the crop factor? (just curious)
It's with a Nikon D300 which has a 1.5x crop and the lens is designed for that sensor size. As a result, unlike full-frame fisheyes, this lens is really small and easy to carry around. The first picture was "de-fished" which turns it into a rectilinear image at the expense of a sigificant part of the field of view. The fisheyes seem to be the only way to get "crazy wide" with a cropped sensor, unfortunately.
I also had an old Sigma fisheye, a 16mm AI, but it literally fell apart despite being an all-metal 1970-early 80's model that was built like a tank. The front element looked like a round glass ball, which was pretty neat.