I see all this talk about hubs. What about an external battery pack. I have two of the same kind that I plan on using on my tour. It is about the lighter than my 80 gig IPOD and can charge any usb powered device for hours on end. I think I have had 25+ hours of use before charging. These were in 5-8 hour blocks, mind you. The device is called Portable Power and is made by Hyperkin. You can find it on Amazon.

If you are going to be away from electricity for a long time, consider using a solar charger. I have a Solio that will charge my power packs, which will in turn charge my usb devices. The Solio also has an internal battery that stores its solar charge.