Circular Panoramic Photosphere

I was just experimenting with a panoramic from Wales, I haven't been doing much shooting lately so I have to play with older photos, it is still only 2 weeks old though. I saw this effect in a recent photo mag and thought I would try it out. This vista is not the best for this technique, the ones I have seen are normally cityscapes, so I must remember to do one next time I'm near canary wharf. The floor of the shot is also an important part, one I omitted on this occasion. I will write a better tutorial when I get a better example.