I use a third party app which can handle recorded voice tags. I use Cyberon Voice Speed dial for which voice tags can be records for contacts or programs.
For bluetooth headset/car conenctivity i use Bluetooth Application Launcher.
This is set to open Voice Speed dialler when i press the blue tooth button to connect. Holding the blue tooth button for 4 seconds disconnects and closes the app. (i have to configure it futhter since disconnecting doesn;t yet hang up the phone though...)
Sorry - i just realized you needed to dictate to your phone. Maybe there also a third pary app that does that.