Here is my solution for travel/emergency power for my small electronics.
I have adapter tips for my phone and some other devices so all I need is a healthy stock of AA batteries. The same company also makes USB plugs for their adapter tips so I can power up from anything with a USB outlet (computer, car adapter, wall wart).
I looked at that, but realized that it uses a proprietary connector, so it quickly got pretty expensive for what it does. In my GHB I have the Duracell version that has a standard mini-USB jack and comes with both a mini-USB plug and iPod/iPhone dock connector, costs about $5 with batteries. Works well, and doesn't mind that I use Energizer Lithiums instead of Duracells.
I just ordered one of these for $3.39 (damn, price went down 9¢) for my EDC, we'll see how it works.