Very cool - I've often thought about trying to set something up like this for situations - mostly on airplanes - where you're allowed some kind of "free messaging" but otherwise don't have any data.
Thanks and yeah, that's another good application of the idea. It's somewhat similar to iodine[1] in that respect. On the ground in the US, this would probably only be useful if you're hiking in a remote area or something like that, due to how cheap data plans are. It might also come in handy if your carrier doesn't charge for SMS when abroad.