Check out this JuiceBuddy. It is a super small iPhone charger that you can even hang it as a key chain. The plugs and charging port (30-pings) are already built in so that you can just plug into a socket to charge your iPhone.
That is not all. There is a hidden feature. Remove the key chain attachment and you can see a USB 2.0 port for you to charge your other devices. Interested? Here is the video.
And here is the link to the website.