The technology acceptance model (TAM) is one of the most widely used models of information technology (IT) adoption. According to TAM, IT adoption is influenced by two perceptions: usefulness and ease of use. In this study, we extend TAM to the mobile commerce context. We categorize the tasks performed on wireless handheld devices into three categories: (1) general tasks that do not involve transactions and gaming, (2) gaming tasks, and (3) transactional tasks. We propose a unified conceptual model for wireless technology adoption. In this model, task type moderates the effects of four possible determinants: perceived usefulness, perceived ease of use, perceived playfulness, and perceived security. We postulate that, under the mobile context, user intention to perform general tasks that do not involve transactions and gaming is influenced by perceived usefulness and perceived ease of use, user intention to play games is affected by perceived playfulness, and user intention to 124 FANG, CHAN, BRZEZINSKI, AND XU transact is influenced by perceived usefulness and perceived security. A survey was conducted to collect data about user perception of 12 tasks that could be performed on wireless handheld devices and user intention to use wireless technology. Multiple regression analyses supported the proposed research model. KEY WORDS AND PHRASES: mobile commerce, perceived ease of use, perceived playfulness, perceived security, perceived usefulness, TAM, task performance, task type, user intention, wireless handheld devices.THE CONVERGENCE OF MOBILE INTERNET and wireless communication technology has promised users "anytime, anywhere" access of information for work and personal communication. Such opportunities include mobile services that support mobile commerce transactions and process facilitation for managing personal activities, mobile office, and mobile operations [1]. However, certain factors hinder access, such as small screen display, limited bandwidth, and multiple functionalities of handheld devices.Research suggests that interface developers need to consider the interaction among the interface design of user tasks, form factors, and application objectives [7, 27]. Mobile commerce assumes that users primarily access the Internet or wireless applications away from their home or office while either on the move or stationary. Since mobile users have only limited time and cognitive resources for performing a task, the design of mobile applications is important. Anckar and D'Incau [2] suggest that services that emphasize mobile values (e.g., meeting time-critical and spontaneous needs) are more suitable for wireless devices. In designing mobile commerce applications, it is essential to determine which tasks are suitable for wireless applications [6] and how to implement the tasks.Human-computer interaction (HCI) studies tend to focus primarily on designing easy user interfaces. There has been little research that provides empirical evidence about how task implementation may affect user adoption of mobi...