Hi all, I'm going on a backpacking trip without my laptop, just my iphone 5s for photos. I'm pretty snap-happy, so I'm a little worried about running out of space on my phone. I can't guarantee that I'll have enough wifi access during the trip to sync up and store my photos online, so I'm hoping to take some sort of storage device with me. Is there anything out there that I can plug straight into my iPhone and transfer over photos? Or maybe even with airdrop/bluetooth? Thanks in advance!