AA battery phone charger
This has to be one of the simplest and cheapest ways to charge your phone while camping, or in an emergency situation. Most of us have plenty of AA batteries charged and ready for use for our flashlights and radios, but using this cheap piece of Chinese plastic, you can also use you AA batteries to charge your phone. You simply insert 2 x AA batteries, plug in your USB charge lead, connect the other end to your phone, and then flick the switch. It even has an LED light built in. Since most of us are already carrying AA batteries in our bug out/car bags, at around $2-5, these little chargers are well worth having in every car, and in every bag. I have used these to successfully charge iPhone 3/4/5, iPod Nano, iPod Touch, and various HTC phones.
Universal USB Emergency Portable 2 AA Battery Power Charger for Mobile Phones XP$6.46
Emergency USB Portable 2 AA Battery Wireless Cell Phone Power Charger Universal$2.84
Universal USB Emergency Portable 2 AA Battery Power Charger for Mobile Phones ZM$5.6
Universal USB Emergency Portable 2 AA Battery Power Charger for Mobile Phones MG$1.8