Google Voice mobile app for Android and Blackberry phones, now uses a feature called "direct access numbers," which makes placing calls much faster.
"Until now, Google Voice app had to make a request to Voice server every time you wanted to make a call to send us the phone number you wanted to dial. Then the call would be connected via Voice access number. With direct access numbers, we assign a unique phone number to every person you call. This means that we no longer need to use your data network to access the server each time you make a call, so calls will be placed much faster," explains Google.
Updates to Android app is available from Android Market, and Blackberry users can download here.