This article was originally posted in January, 2011 and may contain outdated information.

If, despite all the advice you’ve read here and elsewhere, you’ve not created a separate Gmail account to use with your Google Voice service (using this form to attempt to get your existing number transferred to the new account, if that’s your desire), then these links are for you:

1.  Asterisk hack: make your Google Talk client invisible:

It’s been a too-busy-to-write week, but I found some time the last few evenings to brush up my C coding (only hacking at this point, really) to make Asterisk 1.8 do something I’ve wanted from the beginning: Google Talk’s invisible mode for the Google Voice integration. ….. You might want to use this feature if, like me, your Google Voice number is attached to your main GMail account. I don’t use the chat features but I appear online to anyone who has me in their contact list, as long as Asterisk is logged in, and that has the potential to draw unwanted instant messages (that will never get answered).

Full article here.

2. Avoiding the problem of missing calls when you are logged into your Gmail account:

NOTE: Also see: Not receiving some incoming Google Voice calls? Try increasing the priority.

This is posted on the OBiTALK forum, but likely applies to Asterisk users as well.  I specifically suggest that you read the third and fifth posts in the thread (posted by user “Agate”).

Link to thread on OBiTALK forum.

By the way, something I’ve been looking for, for those who use Asterisk 1.8+ with Google Voice but prefer to use the Google Voice voicemail instead of Asterisk’s, is an easy way to get a count of new voicemail messages in a specific Google Voice account. This information could then be used in some type of notification system.  What I’m specifically NOT looking for is something that requires the use of pygooglevoice — since all we want is a voicemail count, that’s overkill.  I’d also prefer a solution that doesn’t require downloading a huge XML file just to extract a voicemail count (since this is something you’d check rather frequently, pulling down about 10,000% more data than you really want just doesn’t cut it).  If anyone know of an elegant way to do this, I’d love to hear it.