this instructable will show you how to make a portable usb charger, using only a few parts.

parts
3 AA batterys
3 AA battery holder
a usb socket (computer end)
glue (elmer, garila, etc)
(posibly some 22 or 24 AWG wire

tools
solder& solder iron (30 watt ish)
(posibly a needle nose)

Step 1: Asimbly Usb Port

find a male USB A port (i got one from a junk printer)
(this will probly be the hardest part to find)
solder the wires either from a batery pack or solder the conector then the battery pack to the 2 outside pins of the connector. (the other 2 are data and left disconected.)
pin 1=+ (positive)5 Volts, pin 4=GND (negitive)
the picture for the type A jack shows the locations of these pins. (if you need more info try www.pinouts.ru)

Step 2: Battery Holder

you can get these at radio schack or prety much any catolog.
i am using one from an old stereo
1.5 volt * 3 =4.5 volts usb runs at 5 volt this is as close as you can get with betteries.

Step 3: Put It Together

take the conector if not soldered to the battery pack yet do so now. glue the connector to the back or a side of the battery holder. make sure you will be able to insert and remove the plug from the port.

Step 4: Ready to Use

put the batterys in the holder. you can use standard or charged rechargables. plug in the cord of the divice to be charged off of this into the port on the battery pack. plug in the divice to the other end and it will start charging.
done

not responible for any thing that happens as a result of the use/misuse of this project

the picture of this step is of my finished project and yours may be different.

(i using mostly genaric pictures because what i used in mine will be rare to find an idintical part.)