If you don't have electricity: Get two batteries and dunk them in the cup of water for 1 or 1 1/2 hours and then link the mobile phone with USB cable to the water! Great improvised technique for those traveling through revolution areas, or maybe just backpacking somewhere and you don't have electricity.

As a background to video, Syria, Yemen and Libya (the three countries currently deadlocked in revolutions for half a year without getting change) are undergoing severe power cuts and gas/deisel shortages so that even generators cannot be run. In Libya war has cut off supplies and production. In Syria and Yemen the governments have applied sanctions of mass punishment against the population and left them without services in general.
UPDATE: Hope no one lost a couple of batteries or stuck a potatoe up their ass. Some of the comments are funny. Personal favourite quoted below!

There is a faster way using a potato without having to wait 1 1/2 hours. Eat a raw potato. Stick one end of the USB cable up your ass and the other end plugged in to your phone. Then blow your nose and you have a full charge.