Some of my sweetest and best cats have been formerly ferals, including the adorable and world-class cutie I currently have, Zizu. Feral cats didn't ask to be dumped by cruel heartless humans to starve or be eaten by coyotes. They deserve the chance to be vaccinated, spayed or neutered, and have some reasonable shelter. Kittens caught young enough can be socialized and make very fine companions. You don't see many dumb street cats, so you're pretty much guaranteed to have a right smart little kitty.
Some of the "suggestions" posted here are just downright stupid and cruel. If that is the image the posters wish to cultivate, I'd say they were successful. They are no one I'd want to waste a minute on.