There are many different ways to make a solar charger for your phone. Its almost been done to death! This is just an instructable to show how to make one for the cheapest price. This is also so easy, all you have to know to do it, is how to find the parts. There is no soldering (unless you want to get fancy), no complex wiring, no dangerous high voltage, and no circuity building. The total price of this project can be as low as $8, if you buy everything online. The things you will need are:
A solar panel that is 6v and 2 watts or better
A dc converter 3v to 5v usb charger
Aligator wires and charging cord
A light source
Step 1: The Solar Panel
First, you need to take the solar panel and find the leads. I bought my solar panel from radioshack, so it came with preinstalled leads. If your panel doesn't have leads, then you will probably have to solder. If it does have leads, attach the alligator clips, one to each lead, and make sure they are corresponding colors to the charge they will carry so that you dont get confused i.e. red to positive.
Step 2: The Dc Converter
The converter I bought was very cheap on ebay. I got 2 for $3. This step will depend on the converter you buy. My converter had the connections right in the corners where it says In+ or In-. All you have to do is connect the corresponding alligator clip on the panel to the right connection.
Step 3: Finishing Up
Now plug the phone in with its charging cable and go find a light source. I used a 90 watt lamp, but outside would work much better. Depending on what solar panel you used, it will take quite a while to charge. A larger panel means more power, but too large will destroy the charger so use common sense. Here is a video of it showing some more info.