While I am not terribly happy with the cost of this Goal Zero Solar Charger, from what have found, it is the best quality and has the most options of any charging system out there. It can be adapted to any charging needs you might have. As with anything, you get what you pay for, and I also appreciate the philosophy of the company and what they are trying to do for less fortunate people of the world.
If you really want to be off-the-grid, these will do the trick! I have a portable unit very similar to this, but what really sets this one apart from that is the ability to charge with Solar, and it has my more options for devices you can connect to it.