From the Motorola Website:
There are several voice commands available for use on your device. To use Voice Search, press Microphone Icon and say a command
Call -------john doe, mobile phone
Navigate--to pizza in Palo alto
Map-------of gas stations
Or simply, say a word and see the search results in the browser.
To voice dial:
1) Press and hold the SEARCH button.
You’re prompted to speak.
2) Say “Call” followed by the name of the contact you want to call.
If Google search by voice finds a match, it dials the contact’s default number.
You cannot initiate voice search from a headset
At this time the using Bluetooth for voice dialing only supports dialing last number. A full featured version may be available via the Android Marketplace.