d0lph1nK1ng Software (OK, that was very hard to type cause of zeros and ones) has mentioned on its blog for a new unofficial google voice application for Palm Pre. This app seems well integrated with your phone book and lets you select contacts from your device to call or with dial pad so you can dial a number if the caller is not in your contacts. You can call or send SMS using your Google Voice number. The app also shows history and certainly how can we miss the voice mails! This app is not yet released and currently under development.
Here are the screenshots that have been pre-released:
