Access to Web applications using hand-held devices is becoming a necessity for gathering information, conducting transactions, and interacting with people, and other information systems. However, developing and deploying Web applications on mobile devices is not straightforward as it might sound. Web pages and applications for mobile environments pose certain unique requirements and challenges, compared to their desktop versions, which primarily arise from small size of the devices, limited input and interaction capabilities, slower communication, and need for tailored content depending on the dynamic context of use. Successful development and deployment of mobile Web applications calls for a better understanding of these requirements and challenges. This paper identifies and addresses these unique requirements and challenges, and presents an overview of approaches and techniques for adapting Web pages developed for desktops for deploying on mobile hand-held devices.