In case you’re interested in a cheap, reusable 9V to USB adapter/charger, AnythingButiPod has a neat step-by-step tutorial up that requires little more than soldering. Or you can always just buy a ...
The project demonstrates how an old AC wall wart was used to create a homemade USB charger for handheld electronics such as Personal Game machine, Digital Camera, or MP3 Player. The project ...