I encourage you to build new and novel multimodal applications using X+V. There are several platforms available:
The Opera browser can be downloaded from http://www.opera.com/. The voice plugin can be downloaded from http://www.opera.com/voice/. A tutorial about using X+V is available at http://www.opera.com/support/tutorials/voice. Opera's X+V discussion forum as at http://my.opera.com/community/forums/forum.dml?id=95.
The multimodal site from IBM, (http://www-306.ibm.com/software/pervasive/multimodal/), contains download information for three browsers:
Two interesting multimodal demos are available at http://www-306.ibm.com/software/pervasive/multimodal/demos.shtml. The X+V programmer's guide is at ftp://ftp.software.ibm.com/software/pervasive/info/multimodal/XHTML_voice_programmers_guide.pdf. The IBM X+V tools discussion forum is at news://news.software.ibm.com/ibm.software.speech.multimodal