Bluetooth and the iphone 3G

This maybe a simple question...

But I can't seem to find Bluetooth that interacts through the iphone 3G via the headset using the voice recognition software.
I hate having to push the bloody talk button on my iphone to find a contact when I am engaged with something :P

Anyone know anything about this?

Thanks,

D.

Sorry, but as far as i know the iPhone 3G doesn't have Voice Recognition at all. Could you elaborate on how you do it at all?

Must be through an external device. A mate of mine hacked his iPhone and his Navigator for pairing via Bluetooth. The Navi then, did voice recog pretty well.