Thought I'd throw a few of my personal favorites from my reletively cheap 70-300mm f4-5.6 IS USM telephoto zoom attached to my current 450D.
Owl was taken at f5.6, 1/800, ISO 400 & 300mm with just a UV filter
Kestrel was taken at f5.6, 1/500, ISO 400 & 300mm with just a UV filter
Owl was taken at f5.6, 1/800, ISO 400 & 300mm with just a UV filter
Kestrel was taken at f5.6, 1/500, ISO 400 & 300mm with just a UV filter