I've been having heaps of fun with my new toy, Nikon's AF Fisheye Nikkor 10.5mm f/2.8G ED-IF DX. I was even more excited when I came across this article at Ken Rockwell's site about DxO Optics Pro, a program that allows you to correct the distortion associated with such wide lenses. I downloaded the free sample and have been playing around with some of the images I took in Cambodia.
Here's an pic from a market in Kampot, southern Cambodia, without any distortion correction:
Here's the same image after DxO Optics Pro's one button distortion correction:
And even cooler, if in Expert settings mode, you click on Max image, you get an even wider image:
I'm pretty sure I'll end up buying this, especially if they add settings for my 18-35 f/3.5-4.5 D.