XVoice provides voice control of X applications using IBM's ViaVoice for Linux (free download at their web site). Both user-defined commands and dictation are supported. It can be used to write letters, write code, control netscape, etc.
Time of day service over telephone using Voicent Gateway, a VoiceXML gateway that specially designed for voice modems. A Free version is available for download at http://www.voicent.com/download. Sample code for interactive telephony applications.