The interface between a machine, which provides a variety of services, and the user (the one served) is described. These experimental telecommunications services include enhanced calling, personal assistance, and electronic messaging. They are felt to be mutually consistent and are perceived at a user's instrument, called a teleterminal. A tree-like structure for the access of services, which is customizable to the point of being user-alterable, is presented and justified. This access software and the physical teleterminal combine the concepts of selection from a menu, traversing a tree, and the relabeling of buttons. An illustration is presented and several generalizations are discussed. The research nature of the project is emphasized.