The number of mobile phones across Japan has exceeded 85 million (as of the end of January, 2004). Mobile phones are regarded as an essential factor for achieving ubiquitous networks in Japan in the e-Japan strategy, which is being promoted by the Ministry of Public Management, Home Affairs, Posts and Telecommunications. Also, telecommunications carriers in Japan have been shifting to 3rd-generation mobile phones, and the development of higher-performance mobile phones has enabled them to be incorporated with custom programs such as JAVA. The paper explains "sMobile," an application package developed to increase operational efficiency in our company. This software enables mobile phone users to use IBM Lotus NOTES/Domino through their mobile phones using JAVA. It achieves utilization of the mobile phone as an information system terminal by linking with the latest state-of-the-art functions of mobile phones.