A new device transforms smartphones into text-based GPS walkie-talkies when cell reception goes down. This capability could prove incredibly useful to consumers, whether they are stranded in a post super-hurricane disaster area, or merely trying to meet up with friends at a music festival.

Last week, goTenna began selling a pocket-sized antenna device that pairs with both iOS and Android smartphones via bluetooth. This “goTenna” shoots out text messages and GPS locations over long-range radio waves. As long as the goTenna is within 20 feet of a phone, goTenna users can employ a free app to send and receive texts and share GPS locations without relying on wifi or mobile data.

Daniela Perdomo, goTenna’s co-founder, told Wired that the idea for the device first came to her while watching super storm Sandy descend upon the New York and New Jersey coast.

“I was thinking, ‘Is there any way to make cell phones communicate, so even in the worst case scenario like Sandy, when you have no power or Wi-Fi, you can still communicate?’” said Perdomo. “The only thing that does that is Bluetooth, and for that you have to be within 20 feet, so you might as well just speak loudly. We figured out that the only way to do that was an external piece of hardware.”

While Perdomo designed goTenna with disaster relief in mind, it soon became apparent that the device had uses far beyond emergency applications.

“Take it with you on your next ski trip, vacation on a deserted island, music festival excursion, field study in a remote area, or simply keep it on you just in case,” says the goTenna FAQ.

By using text messages, rather than voice communication, the goTenna improves on some of the shortcomings of traditional walkie-talkies. For one, SMS messages are tiny, which allows the  goTenna system to function on very little bandwidth, leading to impressive battery life: 72 hours in typical use, 30 hours nonstop. For another, unlike a walkie-talkie or a telephone conversation, both ends of the discussion do not have to be online at the same time. The radios save sent messages until the receiver views the message. Once a message is read, senders get a confirmation that the receiver has seen the message, similar to Apple’s iMessage.

GoTenna will cost consumers $150 for two.