I no doubt am going to get utterly flamed for this, but nevermind.
I am going to plant my colours in the "pro-choice" ring. I think instead of us going that this is sacred from point X onwards (what about the status of the 'person' during the process which turns it into a person?) What should matter is the potential of this 'proto-person' to form an adult. I suppose you could call me a bit of a relativist, insofar that I think abortion can be (although not always IS) justifiable. Many people, from what I am reading dislike anything relativistic, in response, I would have you answer a question:
If I was a mad physicist who had constructed a doomsday device which would destroy the planet, and my terms for me not to do it were that you conducted an abortion on my wife, who wanted one, would you?
Now, if your answer is no, then fair enough, you are a moral absolutist, however, if you say you would, for whatever reason, even if you say that some rules have precedence over others, then your decisions are somewhat determined by their consequences.
I am going to accord with what bluesman has said wholeheartedly. Whilst you can say the woman is not the only 'person' who is important (although at what stage you decide 'person' as opposed to clump of cells is probably more than a minor bone of contention.) The pregnant woman is hardly a disinterested party. Whilst her interests might well be considerably less important than another human beings right to life, they are worth mention. I think if you are against abortion, you will need to use the carrot more than the stick, simply because if someone wants to have an abortion and it is illegal, they can go somewhere it is legal. It unfortunately is common in the republic of Ireland. Perhaps even if we consider abortion categorically wrong, it is perhaps better to allow Women to 'sin' by having an abortion in a hospital where, at least, risk to their own health is much lower. Whilst it might be better if it didn't happen at all, if the woman is committed to this course of action, we surely must try and ensure the least harm comes of it as possible?
As Veronica has pointed out, Abortion is not a 'fun' experience. I am pretty sure women do it, rightly or otherwise, because they think it is the right thing to do. It can certainly be clouded by self interest, or the Womans disbelief that the fetus is really a person, etc. However, if we act to make conditions easier for women, then that is surely a good thing? Perhaps we will ultimately have a method of being able to sustain zygotes from conception onwards via medical technology. This would, hopefully make abortion a null issue. In the meanwhile, surely a compassionate approach which attempts persuasion (like Bgood and Bluesman are suggesting, if I catch their drift correctly) surely quite a good idea? I am pretty sure the moment you step over the line from trying to persuade and help to threaten and intimidate, you lose more than you gain, simply because you gain the reputation as idiotic, scripture bound fundies blind to the world around them.