The stylus-equipped Galaxy Note series is a hit, but is the pen a key factor in the phablet's success? If so, then the rumor that the upcoming S IV will also have a stylus--a first for the Galaxy S series--might not seem so far-fetched. Unlike a conventional stylus, such as Samsung's optional C Pen for the Galaxy S III, the S Pen is pressure-sensitive for better accuracy. However, by including a stylus--and its requisite pouch--to the S IV, Samsung runs the risk of adding unwanted bulk to the svelte smartphone's shell. And who wants an ugly Galaxy S?