Apparently this application allows you to do voice activated dialing on your bluetooth headset
http://www.dfxmobile.com/voicedialerhf
From what I've heard it does require you to assign the camera button to start it. Anyone have a bluetooth willing to try it out? It's a $4 app but as it's available from the market you'd get a 24 hour money back guarantee.
I don't own a blue tooth yet but if this works I think I'll get one.