The MObile Teamwork Infrastructure for Organizations Networking (MOTION) 1 service platform that we have designed and implemented addresses an emerging requirement in the daily business of large, distributed enterprises: support for mobile teamwork. Employees are often on the move and use a wide range of computing devices such as WAP phones, PDAs, notebooks and desktop computers. The service architecture that we have developed supports mobile teamwork by providing multi-device service access, XML meta data for information sharing and locating, and the XML Query Language (XQL) for distributed searches and publish/subscribe. We present the solution that we adopted in our prototype, analyze the shortcomings of this approach and based on our evaluation experiences, list the requirements for a publish-subscribe middleware for collaborative mobile working.