Never thought I would have a second part to this.
Via John Robb, I give you this: http://mobileactive.org/village-base-station-project
Ok, a bit more complex than the analog stuff I talked about here. However, imagine what you could do with this in addition to a little analog gear or high gain, directional antennas?!?
Trying to think outside the proverbial box here a bit.
Portable & flexible? Check!
Resilient? Better believe it.
Adding global reach to your comms for very little effort or cash. Awesome!