As wireless technologies evolve, the coming mobile revolution will bring dramatic and fundamental changes to the world. This revolution has already begun and is gaining momentum. The revolution will impact numerous facets of our daily lives and the way business is conducted. It will provide important data in real time to assist decision makers, exert great influence on communications between businesses and their customers, and transform the way we live our lives. This paper examines issues in providing services via wireless technologies, i.e. mobile services. The paper discusses the challenges facing mobile services, such as changes in business strategies, investment risk, limitations in mobile devices, networking problems, infrastructure constraints, security concerns, and user distrust in mobile applications. Research issues, such as killer applications, usability, user interfaces, mobile access to databases, and agent technologies, are also discussed.