Plotter or Pantser?

Are you a plotter or a pantser?
To some extent I am both :-) If I am not familiar with the main plot of the piece I am working on, I might very well plot the entire manuscript chapter for chapter. If its a subject that I know well, one I've had personal experience in for example, I simply plot out the main ideas and "wing" the rest.
I have several author friends who use storyboards. I've not tried this method yet, but am going to give it a try on my next manuscript.