You know how it goes: you're at a festival, and you get separated from your friends. Desperate to reconnect with them, you pick up your phone to text them, and...no dice. You try calling, but...nope. 

Enter goTenna, a device that allows you to send text messages without Wi-Fi or a cellular signal. How does this sorcery work? In their own words, "goTenna enables you to communicate without any need for central connectivity whatsoever—no cell towers, no Wi-Fi, no satellites—so when you're off-grid you can remain connected. In fact, goTenna will even work if your smartphone is in 'Airplane Mode'!" The goTenna communicates through Bluetooth with your phone (it needs to be within 20 feet of your phone in order to work) and sends the signal out via long-range radio waves to other phones paired with goTenna and within a 50 mile range. Abracadbra! Texting without a signal.

Early adopters get a 50% discount on a pair of goTennas, so you can get one for you and one for your fest-friend (OMG, FFF!) and stay connected in the crowd for only $150.