Google Voice / Sipgate / ATA
Well, Google shut down Gizmo's SIP service, so I went shopping for another SIP service. Sipgate is it. I have a wired phone connected to an ATA connected to my home LAN and routed through the Linux firewall.
Sipgate is very similar to Gizmo, although Google Voice needs to connect to it as a phone number vs. a native SIP server like Gizmo was.
So more details are:
1. A Google Voice phone number that has my Sipgate phone number as one of the phones configured.
2. Incoming calls to my Google Voice number ring my Sipgate phone number.
3. At home, I have an ATA that registers with the Sipgate SIP server.
4. Outgoing calls go through Sipgate and are 1.9 cents per minute.
This all still allows other non-technical people to use this phone without extra weirdness. If calls are initiated through Google Voice online, they're still free.
Still holding back on using this as our main phone. I want to get more time on it before I declare it ready for prime time.