How can I send SMS messages from my Google Voice number without using the Voice app?

I would like to send text messages via Google Voice, as it is the number I give out for voice calls. However, I find sending SMS through the Voice app to be a bit cumbersome. The new widgets improve this somewhat, but it is still awkward. I would prefer something with an interface more like Handcent or ChompSMS. Are there any other apps that support sending SMS via Google Voice?