MiPad is one of the application prototypes in a project codenamed Dr Who. As a wireless mobile PDA, MiPad fully integrates continuous speech recognition (CSR) and spoken language understanding (SLU) to enable users to accomplish many common tasks using a multimodal interface and wireless-data technologies. It tries to solve the problem of pecking with tiny styluses or typing on minuscule keyboards in today’s PDAs or smart phones. MiPad incorporates a built-in microphone that activates whenever a field is selected. As a user taps the screen or uses a built-in roller to navigate, the tapping action narrows the number of possible instructions for spoken language processing. MiPad currently runs on a Windows CE Pocket PC with a Windows 2000 Server where speech recognition is performed. The Dr Who CSR engine has a 64k word vocabulary with a unified context-free grammar and n-gram language model. The Dr Who SLU engine is based on a robust chart parser and a plan-based dialog manager. This paper discusses MiPad’s design, implementation work in progress, and preliminary user study in comparison to the existing pen-based PDA interface.