Please use these instructions at your own risk.I would not be liable for any damage or any consequences!
My inspiration came from this information-http://www.ladyada.net/make/mintyboost/icharge.html
1) Functional Nokia Charger-1 (actually any brand will do, make sure that it works and delivers more than 500 mA of current.Check the same on the specifications of the output of device)
2) 1 USB Female type Connector
3) 7805 regulator( might not be required if the output of the charger is 4.5-5 volts)
4) A potentiometer, any value will suffice, I used 20k.
I tapped the positive and negative of the charger after opening it through wires, and checked the voltage output.The charger mentioned 5 V as output, but in reality was 8.67 volts.!! Important!! Make sure you actually measure this voltage to avoid frying your expensive device.
Once you tap the (+) and (-) of the outputs, solder the circuit according to the following diagram( One of the images)
The D+ and D- need to be both at 2 volts.Use the potentiometer to adjust this voltage. Use a multimeter to confirm this voltage is available on the pins.
After you solder, find a place where you can fit the USB connector so that you can cut out a space for the connector to come out. I used a dremel to make a clean cut.
Once done, close the cover of the charger and test again. If you plug the phone, it will automatically disconnect the ipod from charging due to insufficient current.