Mike and I went out shooting with with our Rokinon mirrors on friday. Some crazy shots and while the mirrors lacked the resolution/contrast, one can't deny the price vs. the reach as well as the close focusing ability.
All shot with the Rokinon 500/6.3, resized for web. (still a little soft haha) Most shot at higher ISOs on a K200D.
That does look like fun. I think one of these (maybe the 800mm varity) is next on my "fun stuff to buy list". Actually, maybe I should get one before I go on vacation..