I am so glad that you both liked it.
I shot this with the little Nikon AF Fisheye NIKKOR 16mm F/2.8D. It's a very small lens and can slip easily into a pocket.
I do de-Fish images which I have shot with it sometimes but this one was processed at full-Fish with Lens Profile Corrections turned off.
Exposure was: 1/5000, f/11, ISO 10000 (That flag was really whipping around in the wind.)