The wireless application protocol (WAP) is an example of technology that has found itself ìstuck in the middle.î Its introduction is not a clear success, especially when compared to the high expectations during its launch at the end of the 1990s. However, it is not dead. There is a significant number of users, and the telecommunications and content industry continue to invest. The interesting phenomenon is that ìnonbelieversî say, ìWe donít need WAP,î and that ìbelieversî say, ìWait until we have resolved the technical problems.î This paper discusses a field experiment that tested the hypothesis that mobile workers benefit from a specific kind of WAP technology: the mobile office. In an 8-week pilot, 40 mobile workers of an IT services company in the Netherlands received a WAP phone providing them with mobile access to their agenda, mail, directory services, outstanding invoices information, and resource availability. They could also access public infor- mation services such as stock market information, weather forecasts, and traffic information. For research purposes, we distinguished two groups of workers: relationship managers and technicians. We expected that relationship managers would benefit more from their WAP phone than technicians. During the 8-week period, all participants were closely monitored on a daily basis. We collected data on perceived usefulness and on the impact of using the mobile office on the efficiency and effectiveness of the work of relationship managers and technicians. The results show a clear increase in perceived usefulness and also in effectiveness, especially for relationship managers. In our discussion section, we argue there is indeed hope for the believers. Mobile workers have a positive attitude towards WAP if it brings their working environment within reach at any place. As the initial focus for WAP application was on mass private market services, this may explain the initial lack of success of WAP.