Tiny USB-to-Lightning charging cable

I was at a conference last week and a woman asked if I had a charging cable for her iPhone. I let her borrow my inCharge cable ($12 on Amazon), which uses magnets to securely fold around a keychain. It comes with the keyring.

Combine it with this itty-bitty $5 battery pack (use code XMPQBIDX) and you have a very portable charging kit