I prefer busty women and have a knack for spotting them in a crowd no matter how they try to disguise it. If I saw madame_zora or Kat on the street, I would definately notice them but not gawk, stare or leer. I whole-heartedly agree that it is rude and insulting to stare at a woman's breasts; especially when you are talking with her.
What I don't like is when a woman dresses provocatively in public and then leers at you when you notice them as they walk through your field of view. OF COURSE when a person walks right past you, you are going to notice them.
One time, a sassy little wench wearing an extremely low cut shirt actually had the nerve to ask my friend and me "what are you looking at?" I replied cooly, "if you don't want men to look at your breasts, maybe you should consider covering them up" and immediately turned away from her, continuing the conversation with my friend.
I agree with what madame_zora said earlier about girls not being able to have it both ways. If you don't want the attention from the guys (or women) then don't wear a shirt that is cut so low that your areolae are exposed! B)