I got the chance to test the new Canon 8-15mm fisheye lens recently. This is the circular fisheye image you will get at 8mm on a full frame full frame sensor. The lens actually begins to vingette at 14mm on a 5d mk ii, so the usage is rather limited on a full frame. On a crop body, there's a lot more flexibility. 15mm on a crop will show a bit of distortion, while it begins to vingette at 10mm. In my opinion, this lens is a winner on a crop, but limiting on a full frame (i.e. you may as well get the 15mm Fisheye at a fraction of the price).
I am holding a contest on my Facebook Page! Take any picture between now and October 9th relating to the theme "inspiration" and post it to my Facebook wall. Tell me a little something about the image and I will choose a winner at random on October 10th. Winner will receive a 36x24 print of their choice -- either one of their images or one of mine!
(shipping outside of Canada is not included, but can be mailed to the winner at actual cost)