I kinda like the little Modulo. It’s a set of battery packs for charging your gadgets, with the gimmick that they are stackable and work on concert, letting your tune the weight/power ratio depending on which gadgets you’re using, and how long you’ll be away from mains power.
They also look cool, like little game carts from the 1980s.
One (2,100mAh) Modulo will juice one iPhone, from empty to full. You can add more to either make the backup battery bank bigger, or to charge several gadgets at once. The maximum is five units, and that will give you 10,500mAh, and an included “smart attach” lets you stick the battery to the back of your iPhone.
The colored bricks come in packs, with one short microUSB cable included – you’ll need to supply your own lightning cable or adapter.
Prices start at a reasonable $20 for a kit with one brisk, once cable and one smart attach. The catch? Kickstarter.