The charger in the picture it's already working - it already charged my cellphone last night. But it still needs to be closed inside some case, that should be the 9v battery case kept from it's disassembling process.
However, here goes the instructions, with the electronic scheme included...
Step 1: Materials
And the list of components and materials is:
1 old 9v battery
1 USB port type A (female)
1 Regulator 7805
1 green LED
3 resistors 220R
1 empty case (optional)
Step 2: Schematic
Step 3: Solder the Components
Pins 1 and 3 must be softly lifted up, in order to solder the other components, according with the scheme of the previous step.
One resistor is connectd in the positive pole with a minor size than the base, in order to connect to the Anode of the LED, making a series from the positive 9V pole to Pin 1 of the Regulator.
Pin 3 of the regulator (output 5V) is then connected directly to pin 1 of the USB port, soldering a wire.
The Data pins of the USB connector are connected with 2 pull-up resistors to the pin 3 of the regulator
To finish, pin 4 of the USB port it's connected with a wire to the negative pole of the battery, where it's already connected pin 2 of the regulator.
The result must be like shows the picture, where we can see the charger charging the battery of my mobile and we can read in portuguese: "Bateria está sendo carregada" - Battery is being charged... ;)