Apparently Cheetahs are really easy to tame and have never been known to turn on humans (unlike other big cats which are highly dangerous even if raised from a cub by humans). It seems that they have been used since at least 3000bc as hunting companions. The only reason that they haven't actually been domesticated is that it's almost impossible to breed them in captivity.
No particular reason for this post I was just idly reading stuff and this caught my fancy. Pity I don't have a long enough garden for one to exercise in or live in a hot country. Bet you wouldn't get broken into either as a big cat would put the willies up any would be burglar.