Script Summary: Checks Google Voice for new items (SMS, voicemail, and missed calls) every 2min, and displays Growl notifications and total count on the dock badge.
This script queries the XML returned when the refresh link above the inbox is clicked. The page content is not actually updated, but Growl will display a notification and the dock badge will be updated with the total unread count.
Tip: to refresh the page content click refresh above the inbox rather than refreshing the whole page to keep growl from redisplaying notifications.
If you have improvements, please fork at github! http://github.com/cjmartin/gVoiceGrowler/tree/m...
The original version of this script checked for mew messages/calls every 30 seconds. I thought that was a bit much, every 2 minutes is fine for me; if I need updates faster I'm probably actively using the app.