If it is a phone that has a mini or micro USB input you could use a 5v regulator (2 dollars at radioshack) and a 9v battery.
You could buy a power bank for iPhone from online shop. You would find many kinds of power bank in the below website. Hope I helped you.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.