In an era when workgroups can be widely distributed geographically, tools to maintain lines of communication among group members become critical. Furthermore, the tools become even more useful if they connect more than two people together at a time. Many telecommunications technologies have evolved to address this need.
Conference calls are an example.
Another example is a hypermail archive. Multicast videoconferencing over IP is another. A hypermail archive maintained by a central server and accessible from desktop PC clients or handheld clients. An administrative archive holding things like important group phone numbers and meeting minutes. This is also maintained on a central server and accessible from desktop clients and handheld clients.