As the name suggests(in spanish) my motto is "something out of nothing" and in this case "nothing" is the energy source, which is the sun light, actually it is not really nothing, but because it is free I call it "nothing". Let's rebel against profit thirsty energy companies and harvest out own energy! Don't forget best things in life are free! ;) A charger for small portable devices like mobile phone is a good start. Very easy to make, suitable for beginners with very little knowledge in basic electronics. Keeping it simple!
Portable, lightweight, waterproof and can be positioned in 3 ways:
1. Position it in 45 degree angle ( I did not measure the angle just did it by the eye and please note that the leg should be shorter, then the panel) facing the window up to a meter away, if indoors. You just have to experiment a bit, if it doesn't charge, move it closer to the window.
2. It can be attached to the bag or ruck sack, by placing leg in a pocket with your phone plugged in, so you can charge while out and about…
3. Can be hung on the window with the string, so even in limited light you can still get charge, I would recommend silicon/rubber suction hook or you could simply attach the sucker to your panel, though this would be a compromise on minimal appearance.
Another feature is battery-less , this means phone is charged directly, so you have to remember to charge your phone at day time, although if you do forget it might still get charge from electrical lighting at your home, if it is bright enough. The idea behind this is to reduce unnecessary components to make it more lightweight for mobility as well as minimising damage to environment, and in my opinion it is bit wasteful to charge battery with battery and some batteries like conventional AA have short cycle, this can't be good for environment surely. And from selfish point of view this would add additional cost and consequently would take longer to pay off.
Update: Since uploading my tutorial, decided to improve design and reinforce for durability, the top pictures are of new charger and the last picture is of the old one. Now the USB box can be twisted up and down in 90 degree angle, which makes it easier to position on the ground and a lot easier to fit it in the bag. Added step 4 to explain how.