If you truly want to get off the grid but still need to use your iPhone, check out this new Indiegogo crowd funding project called the CrankCase.
The CrankCase is a durable case for the iPhone with a built-in hand-crank charger. Crank it for five minutes and get up to three hours of life for an iPhone 5. If you can only spare one minute of time to crank, you can still add another 40 minutes of talk time to your iPhone.
Ampware doesn't plan to start shipping the CrankCase until October, 2015, but you can pre-order now starting at $49.99 — the retail price will be $129.99 if the product makes it to market.
The developers also plan to produce a CrankBox device; it's a more universal charging mechanism that works with any smartphone or USB-powered device that can charge up from a 500 mA output.
If you're the sort of person that likes to get away from it all but still wants to be able to call, text or use apps in a pinch, the CrankCase and CrankBox might be really appealing. If you have any sort of repetitive strain injury on your wrists or lower arms, though, you might want to pass on this one.
CrankCase and CrankBox are really neat ideas. Hopefully they'll be able to take it to the next step — they've given themselves until April 18, 2015 to raise $50,000 on Indiegogo. You can also get more info on the Ampware Web site.