I am glad somebody already put this in the wish list. In India the termination between IP & PSTN is not legalized yet - except some specific operators. Not open to public yet. This is due to some national security issues.
The problem is most of the GSM Gateways are expensive, in the range of $150 - $200. It is really expensive. It would be useful if an Obi model available with integrated GSM gateway. Even in US it would be useful, we can make it use like a 911 trunk. Please have model with integrated GSM Gateway.
@Shashank
I am already on this mission. I have a Obi110 in India and Obi202 in US. I need to change digit maps/dial plans to route calls appropriately. I plan to buy of of the cheapest GSM Gateway available in ebay - this just works on two frequency range, perfect for India costs about $30. I could bridge Obi110 with a GSM SIM - the calls could be as low as 0.1c/min. Lets see how this is going to go.
I will let you know the outcome.