There are lots of different ways to charge your phone on the go whether it be with one of many USB battery packs or with a expensive and useless hydrogen fuel cell. A brand new way to charge your phone on the go called USBeast is now available which is especially good for workmen and women who use power tools.
The USBeast is a small device that looks similar to a normal USB plug but instead attaches to the battery from cordless tools, a full list of compatible devices is available from their kickstarter page. Most of these batteries are around 4000MAh so will charge a iPhone over six times and most other phones slightly less. One of the big benefits of this charger is that it can help reduce the costs over a standard charger, it is important to note that the MaH rating on rechargeable batteries are at a set voltage so drill batteries will charge a phone for much longer than an equivalent USB battery pack. The below video explains the charger and how the USBeast works.