We've just posted a link to a 15 minute interview from ACM with David Cohen, the head of Google's efforts in speech recognition. I've also included links to a few (of many) other companies doing work in this area. Nexidia is one of the companies. Way cool!
http://www.resourceshelf.com/2006/09/11/search-briefs-podcast-with-head-of-googles-speech-recognition-efforts/

Direct to podcast:
http://acmqueue.com/modules.php?name=Queuecasts&id=10