Smartphones can connect two people anywhere in the world, assuming both of them have service. Stumbling into an immensely large crowd of people all trying to use their phones at the same time or wandering into a patch of land that a carrier doesn't cover can instantly sever someone's connection to the outside world. This is typically inconvenient, but sometimes it can be life-threatening. That's why goTenna isn't just a potentially cool piece of upcoming tech, it may end up being a necessary one.
It's now been more than seven months since we first caught wind of the Serval project, which promised to allow Android users to make phone calls when conventional cell networks aren't available or simply don't work. Recently, however, the team's initial stab at network-free communication - an Android app called "Serval Mesh" - has landed in the Market.
As briefly mentioned in the above video, the Serval team also has another form of network-less phone calls in the pipelines: an inexpensive, relatively small phone tower that can be dropped into disaster areas by air.