Not a coder or havker by any means, but was browsing my Pre and found that under /etc/audio there are 5 files prefixed with "voice_dialing" :

voice_dialing_back_speaker
voice_dialing_bluetooth_sco
voice_dialing_front_speaker
voice_dialing_headset
voice_dialing_headset_mic

Any way to tell what these do and if there is any way to leverage them into a homebrew voice dialing app?