The key to taming a feral cat lies in food. Baby food and canned cat food work well to get the kitten slowly used to your presence. Feed this special food twice a day but leave dry food out at all times. Slowly begin touching, petting and holding the kitten for a few minutes a day. Gradually increase the amount of time spent handling the kitten. Within a few days or up to a few months, the kitten may eventually become comfortable around you and eventually be tamed enough to become a pet.
To learn more, read Care of Feral Cats.