Originally Posted by
gfunkdave
This sounds like a fun techie project, but I think it's far easier to just buy an ObiTalk device and connect it to a Google Voice account. Free calls to the US and Canada, and cheap calls to many other countries.
That get's you the free phone service. However, it doesn't get you all the PBX features. Incidentally, I use an Obi device to link my cellphone to my system so that, when I'm at home, calls to my cellphones ring on my home phones.