CyanogenMod nightlies now let you use any messaging app for your Google Voice texts
The app will sync your existing Google Voice messages into your messaging store. New Google SMS will be received as if it were a normal SMS. When you send a message out from your messaging app, it goes out via Google Voice." Goodie. Head over to the source for installation instructions.Here's the feature, integrated in current (after July 1st) nightlies, in a nutshell: "
source: KoushikDutta (G+)