Plotting vs Pantsing

There are two basic approaches to developing stories once you've thrown the spaghetti. One, you take what you have, sit down at the computer, and write whatever comes into your head (also known as "writing by the seat of your pants. Hence "pantser"). Or two, you take what you have, sit down and plot it out first so you have a roadmap to follow once you are ready to write (also known as "plotting").

Reading:

2 plotters.doc These are two real-life, published authors who are both plotters. Note that their styles are very different, however! 

Writing Journal:

Are you a plotter or a pantser? What are the pros and cons of working this way?