Most small electronic items include USB chargers today. Which means they might have to get charged from another device, similar to a laptop or computer, which has a USB port. Despite the fact that USB charging is becoming pretty pervasive, it may also be inconvenient. However, power bank chargers give a fast, less complicated, as well as safer solution.
http://www.youtube.com/watch?v=lm3_B3efcVE
http://www.wat.tv/video/12331293