With Locale or Tasker and the GVoice Settings Plug-In you can control automatically which phones in your GV account should ring, based on all the great conditions Tasker or Locale offers, like your Location, SSID or Time. On top of that you will be able edit the settings for Do not disturb, Call Presentation, and Voicemail Greeting - all of that not only for the general setting, but also for each Group individually - if you want.
Locale Plug-in - it will not run without Locale or Tasker.
* * *
This application is not affiliated or endorsed by Google Inc or Google Voice, Inc., but instead from an non-related, individual developer who wants to make your mobile life a little bit easier.
* * *