Hello to everyone!
I saw this post and I remember my old phone had voice dialing feature...I did not use it much though 
I do not remember how to start up a session but I believe you need to tap the microphone next to the Google bar.
As per manual:
From an open Voice Search dialog, speak the following words to
access additional features:
listen to [artist/song/album] plays the selected song.send text to [recipient] [message] opens the Messaging screen.navigate to [address/city/business name] provides directions via
Google Maps™. Use either an Address name, Business name,
business type, or other navigation information to get the desired
directions.
call [name] opens the phone and automatically dials the contact.
Hope it helps!
Cheers
I verified the Samsung SGH T589R user guide and found no mention of voice dialing.
You take a look yourself on Samsung's website, maybe I missed it.
