Nice. What are you shooting with? I have an 80-200/2.8 I use on my Nikon; 200mm doesn't get in that tight for me at 150'.
I was on a trip once where I got to use a Canon setup with the 600mm/usm/is lens and a 1.4 adapter. That was a SWEET setup for wildlife and birding. The lense was so big, it had it's own backpack. The people it belonged to, they called it "Junior" /forums/images/graemlins/wink.gif It was a really nice setup to use; they let me run a couple of rolls of film through it(Canon body). 'Course, it was also about a $11k setup with lense, body, tripod ect.