Turn your cell phones into walkie talkies

goTenna

A collection of goTenna devices act as a free network that allows you to use your cell phone as a walkie talkie.

“Barranquitas is a small town located in the mountainous center of the island, where lacking telecommunications the people were getting information around the old-fashioned way: walking … but a handful of goTenna devices in strategic locations made it so that, for instance, instead of walking 40 minutes to the hospital to ask for medical aid, a person could walk 3 minutes to the church, where they could send a message to the hospital instantly.” Learn more about it at TechCrunch.com.