Are you in the market for a fisheye? This one will only set you back $160,000. Nikon created this extreme wide angle lens back in 1970, for the Photokina trade show. It's the Nikkor 6mm f/2.8, and it has a 220º field of view. The lens weighs about 11 pounds, with a minimum focusing distance of 25cm. When it was first introduced, it was the widest lens available. They only made a few hundred of them, and it took Gray's of Westmister six months to track one down. Kinda makes spending $1,600 on a lens seem like a great deal, right?
Here are a couple of sample images:
From Amy Hobbs: