It's no secret that more and more people are opting for touch-based smartphones and tablets as their computers of choice: iPads, iPhones, Androids, now BlackBerrys, and soon <a href="http://www.infoworld.com/d/mobile-technology/watch-out-apple-windows-8-could-trump-the-ipad-172971">Windows 8 PCs and tablets</a>. For developers, touch-based systems means grasping a whole new set of guidelines, including understanding their audience's new context and careful interface design, say prominent developers in the touch space.