My turn:

A woman and I live in a small town. She needs an abortion and I'm the only one with a car. Am I obligated by her right to an abortion to drive her the 200 miles to the big city so she can get one?

My students want to put up posters that I find offensive but are perfectly legal. Am I obligated to help them do it?

Some guy walks up to my house, knowing that I have some extra guns kicking around, and invokes his right to bear arms. Am I obligated to give him one?

Do I have to spend the rest of my life in a blur of facilitation to make sure that every right that people have that they would like to take advantage of is made easier by my actions?

Or is there some point at which it is permissable for me to say "no...even though you have a right to X, it is not my resposibility to facilitate your use of that right."

We can play slippery slope (man that sounds dirty) all day long if you like, but it's not going to get us anywhere because both sides of this issue are bad options. Women should be able to get the pill or RU-486 or whatever they like, but people should also have the right to say "no" to something they find unethical without being punished for doing so. So there will be negative consequences no matter what happens.