Motorola Droid :: Google Voice SMS Native Integration

Is there a setting, as with voice calls, to have all SMS commands directed through Google Voice? I've canceled my Verizon texting plan and want to send all of my texts through Google Voice. Obviously I can do this by composing messages through the GV app, but I would like to click on a contact's page and have GV automatically open to send the text message. Much like Handcent opens when you select a contacts texting option, when you have Handcent installed. When I select the text message option from a contacts page (or press their contact picture and then select the text option), the Droid opens the standard text message application to send the text. Interestingly, if I go into the call log, select a recently called number and choose "send text message," it opens Google Voice to send the text message. How do I get the same functionality as above, so that selecting text message from a contact's page or shortcut uses Google Voice to send the message?