A Palm-size PC is a mobile companion to a Windows-based desktop computer. It incorporates many of the graphical user interface (UI) elements that are familiar to users of other Windows-based platforms. These elements include a desktop, a taskbar, windows, dialog boxes, menus, and controls. However, unlike other Windows-based platforms, the Palm-size PC software supports voice and ink input; has a small, portrait-oriented, touch-sensitive screen; and relies on user input with an input panel and stylus, instead of a traditional keyboard. Though the principles of user interface design discussed in previous chapters also apply to Palm-size PC applications, this chapter focuses on design considerations specific to a Palm-size PC.