Cloning for parts? Hell yeah!... sorta
See, it would be cool because of stem cell stuff. and DNA fixes and stuff. We wouldn't need the "let nature get rid of the dumbasses" as we could just fix the physical problems of people. Then we would be able to focus on the minds of people and not the bodies (yeah art, i know i know... as MUCH.. they still would....)
As for parts? well if you lose an arm or something, sure.. but to prolong life? I'm not sure I agree with that. Why? Overpopulation, thats why. If no one is dying and people are still being born.. then the death::Birth ratio gets skewed. NOT a good thing. How would you like being 14 years old, and learning that you've had a vesectomy at birth and can never have kids simply because of all the cloning going on, they can't afford it? I'd hate my life.
Cloning for extra people? No! They will have a mind like us, thus they are no different than us. We don't differentiate Test Tube Babies, so why cloned babies? Extra people would only be needed if we ourselves became an endangered species. So then you might say "what about extinct species?" Again to you, I say No! Why? I mean they did once exist in our society, so why not bring them back? Because life has evolved to them no longer being part of it, thus bringing them back could potentially seriously fuck things up.
Again, what if we could even (somehow) clone the mind/personality of a person? (I doubt this.. as you cannot dupe one's soul) This wouldn't really be good. First off, it brings that over population thing back in, as you won't ever really, DIE. On top of this what if you ended up NOT dying? Then there would be TWO of you with the EXACT same minds. That aint gonna be good. There was an episode of this on The Outer Limits. A guy cloned his wife and downloaded her mind into it. She was in a coma, so he justified it as he couldn't bear losing her. So after it worked, he went to have the plug pulled on her, knowing that she would still be with him. When he got there, she wasn't there, but she wasn't dead either, she had just recently checked out! Not good, now there were two of them..... he wanted the REAL one, not the cloned one.. jealousy ensues.. it doesn't end very well.
So to cap it up. To use "clones" for stuff like stem cells and stuff to fix people's physical impediments is a good thing. But to clone to ensure longer life probably isn't as good as it sounds, not unless you think you could live the life as in Soylent Green.
Thoughts?