U-commerce extends traditional commerce (geographic, electronic, and mobile) to a world of ubiquitous networks and universal devices, a world in which users can access networks at any time from any place, using a range of devices to invoke unique and personalized services. As such, u-commerce presents a new perspective on time and space. Specifically, four constructs are identified that form the fundamental dimensions of u-commerce: ubiquity, uniqueness, universality, and unison. Ubiquity allows users to access networks from anywhere at any time, and in turn, to be reachable at any place and any time. Uniqueness allows users to be uniquely identifiednot only in terms of their identity and associated preferences, but also in terms of their geographical position. Universality means mobile devices are universally usable and are multifunctional. Unison covers the idea of integrated data across multiple applications so that users have a consistent view on their informationirrespective of the device used. This dissertation undertakes an experimental investigation to examine how two of the four u-constructs, namely ubiquity and uniqueness, impact individual task performance, perceptions of usefulness and ease of use across differing levels of ucommerce technology and a variety of tasks. Four different treatment groups are created, each varying on combinations of high or low technology ubiquity and high or low technology uniqueness. Ubiquity is simulated by providing wireless technology (or not); uniqueness is simulated by providing location-based services (or not). A total of 117 senior level MIS students served as subjects for this study. The major findings of the study are: Wireless technology was perceived to be very useful for location-dependent tasks. None of the technology treatments turned out to be superior in terms of perceptions of ease of use. However, in situations where technology severely lacks the ability to fit the task at hand, perceptions of ease of use decreased dramatically. Compared to measures taken prior to the experiment, perceptions of usefulness and ease of use are significantly higher during the experiment for every task set. Achieving high performance of non-location-dependent tasks was irrespective of the technology used. For location-dependent tasks, wireless technology in combination with location-based services led to major performance impacts.