One of the problems with having more than one portable gadget is that you're often obligated to carry around several chargers--not all devices have the same charger jack, after all. Some of us also have separate chargers just for the car. If you're not near an outlet of any kind, you either have to go without power or get one of those emergency alkaline battery chargers. All of those different chargers can add up to a lot to carry.
The Trans4m Multi Power Source, however, combines several charging methods into one portable unit. At first glance, it looks rather bulky, and is about the size of a large power brick. But there's a reason for its size--it houses up to four different charging options. You can plug it into an AC outlet, or a DC outlet in the car, hook it up to a 9V battery, or use two AA batteries. On the back of the Trans4m are two USB slots so you can charge two devices at once.