Two similar but different VoIP devices to augment home wireline with VoIP:
PhoneGnome: PhoneGnome answers ooma's call
ooma: ooma chief talks with FierceVoIP
There's a bit of a debate in the comments to both articles, with rabid supporters in each camp.
There is a really interesting tidbit in one of the comments from the PhoneGnome CEO:
The PhoneGnome box could be plugged into the Ooma box to enhance (or augment) the ooma service with additional features and capabilities, whereas the reverse doesn't apply to the ooma box. A PhoneGnome box would augment the user of ooma service with new features like (1) softphone (use your ooma account on your PC at Starbucks); (2) use ooma service on your mobile phone; (3) use an alternative VoIP provider for international calls to get cheaper rates (or even free); (4) use your Ooma service from alternative locations (say outside the US to make free calls to anyone in the US, or on a wi-fi phone from a hotspot).
I think this means that one could connect the PhoneGnome box to an Ooma service and then set it up so one could place calls via SIP to anyone in the U.S. In other words, I could use a wi-fi phone at work to make free calls to anybody in the U.S. Or I could call any U.S. number free from outside the U.S. (say from India to the U.S.) I guess I could do the same thing by connecting the PhoneGnome box to a Vonage account for that matter, but it's an interesting twist to the Ooma line sharing scheme.