This is my next: an iPhone charger on my keychain
The worst part about having an iPhone 5 is trying to charge it. Most people I know have some dock, or speaker, or charger for an old iPhone or iPad, but almost nobody has a Lightning cable handy when I need one – which is all the time, because my iPhone 5 now lasts about six hours on a charge. So I'm forced to carry some terrible combination of external batteries, chargers, and anxiety around with me.
Except now BlueLounge offers the Kii, one of my new favorite tiny-but-brilliant ideas. it's a Lightning connector, connected to a USB connector, connected to a key-shaped head that keeps it on your keychain. For the price of $40 and one extra key in my pocket, I now have a charger with me at all times – all I need is a spare USB port, which I can always find or borrow or surreptitiously steal while I sit in a Kinko's pretending I need to print things. The iPhone 5 charges really fast, and a few minutes of power is usually enough to get me through to my next fix — the Kii makes that ridiculously easy. It's also a super-handy tethering setup, for when I need it.
It's available for Lightning and 30-pin connectors (but 30-pin users should probably just bum off their friends' old iPod docks), and costs $20-$40 depending on what you need. It's awesome. You should get one.