1. A system for establishing a global speech user interface (GSUI), comprising: a processor configured for performing speech recognition to transcribe spoken commands into commands acceptable by said communications system; said processor configured for using the transcribed spoken commands to navigate among applications hosted on said communications system; and said processor configured for displaying a set of visual cues to guide a user in issuing proper spoken commands, said visual cues comprising: a set of immediate speech feedback overlays, each of which provides non-textual feedback information about a state of said communications system; a set of help overlays, each of which provides a context-sensitive list of frequently used speech-activated commands for each screen of every speech-activated application; a set of feedback overlays, each of which provides information about a problem that said communications system is experiencing; and a main menu overlay that shows a list of services available to the user, each of said services being accessible by spoken command; wherein said main menu overlay comprises: a first sub-menu overlay specifically for access to an interactive program guide system; a second sub-menu overlay specifically for access to a video on demand system which provides access to a library of video content; and a third sub-menu overlay specifically for access to a walled garden system which provides browser-based Internet service; wherein each of said sub-menus provides a set of speech-activated virtual buttons.