Woo-hoo, picked up a 16mm Sigma fisheye off ebay for a song. It's an older lens, and it's Manual Focus -- but it works in all modes on my 9000 and wide-open 2.8 on the 7d. So I'm pleased, especially for since it only ran me like $100 US. I'd say it's the fastest turnaround I've ever had on eBay -- I won the auction at 9pm yesterday and had the lens in my hands by 1pm today. I guess it helped that the seller was in the city and could do an in-person dropoff... ;)
It's one of those lenses where you can unscrew the front element and put little 20mm filters on the inside element. I shot this with the front element off, and it focuses down to around 1cm with microscopic DoF. I can see myself having some fun with that in the future.
