I heard that Yahoo! experimented with cheetahs for a while. They are super fast and have great eyesight, but they proved to be "not-so-easily-controlled." Not used to domestication and life in a typical office setting, the cheetahs quickly became restless. Dispite many attempts to train the cheetahs to "sit quietly" they never quite got it. Furthermore, the cheetahs were never actually able to recognize or rate any web pages. It appears that their "fantastic eyesight" is not meant for the aging CRT technology at Yahoo! So, after 2 trainers and 3 support staff were mauled to death, management decided enough was enough. The cheetah search engine was abandoned. They should have thought of using pidgeons.