No, I don't take notes. Especially because I read mostly fiction and I like to maintain my flow of reading to enjoy the story.
I have very few books on my "keeper shelf". These are mostly self-help/inspirational books. I have them underlined and highlighted like crazy so I can go back and see what struck me and helped me the first time I read it.
Sometimes, I'll write a quote or saying on a sticky note and put it on my wall where I can see it often.