It's a cellphone charger. It's an i-Pod charger. It's a backpack? FTF's green staff tests this solar backpack in extreme environments.

With society's ever-increasing dependence on tiny wireless devices for communication, entertainment, and navigation, the biggest inconvenience many travelers now face is the elusive power outlet. Whether you need a charged cell phone for a day trip or an international adventure, it can be a challenge to find a place to recharge your electronics.

Voltaic Systems has created solar powered backpacks and messenger bags that harness the sun's energy using solar panels on the face of the bag. Employing a matrix of deftly hidden wiring, the solar "juice" is channeled to a small battery pack or directly to your device.

We tested the Voltaic Backpack, however there are three other varieties available: the Converter, the Messenger, and the Generater (prices range up to $599 for this super model, because it's the only pack with enough power to charge a laptop). Made from 100% recycled soda bottles (PET) the Voltaic Backpack appealed to us from the get-go with its "green" friendly form and function.

Included with the handy day pack, is the 7.2 volt battery pack, a car charger, a car charger socket, an AC charger for a wall socket, a USB adaptor, and a variety of adaptors that fit many (but not all) cell phones and other hand-held machinery. The wall and car chargers are included so that when you do find a stationary power source, you can charge your battery pack in preparation for a trip and then any time spent in the sun will help to keep your battery pack fully charged.

Without any wall or car charging, the battery needs about 8-10 hours of sun exposure to become fully charged but you can start charging a device as soon as the pack is receiving solar energy. However, don't be distraught by a cloudy day. The pack merely needs exposure to the outdoors to begin charging even if the sun appears to be hiding. In fact, we left the Backpack sitting against a sliding door that receives sun exposure and the battery still was able to achieve full charge from inside.

Test Runs: Beach & House

With all those wires and electronics, we decided to take the Backpack for its first test-run at the beach. The continual assault of sand and a few sporadic thunderstorms served as a good test of durability and functionality. Inevitably, sand found its way inside both main storage compartments and the two smaller side compartments but neither the battery nor any of the wiring seemed to be affected and the waterproof, scratch resistant solar panels were not harmed by a brief summer storm. For bathing suit bedecked families who spend the whole day on the beach but need to stay in contact with the fully-clothed world, the Backpack can easily receive enough sun exposure to charge cell phones, PDAs, small cameras, GPS's, and i-Pods.

On our second outing, we allowed the Backpack to fully charge at home and then took it out for a day in New York City. Although it did feel slightly heavy when it was stuffed to capacity, its hard to argue with a 3.5 pound bag that manages to hold its own solar panels, wiring, and battery pack while still being well-padded and reasonably comfortable. Not to mention, it houses a padded laptop sleeve and still leaves room to carry around school books or miscellaneous travel necessities. With a charging cord that connects from the battery directly to the cell-phone holder on the right strap, it was super convenient to have our mobile fully charged and easily accessible all day long.

User Friendly Support

The informative website contains detailed directions and pictures that can help you decide which voltage to use or which adaptor fits your phone. You can also use the site to purchase replacement parts or additional adaptors if need be. And, the one-year warranty covers any potential malfunctions or broken parts for the first year that you own your bag.

So what are the drawbacks? Despite the array of adaptors, there isn't an adaptor that fits every single cell phone or PDA on the market. However, in a pinch, you can use the car charger and the specific device charger to connect to the battery pack.

You need to know the voltage requirements of the gadget you are charging. You can usually find the voltage requirement marked next to the DC power in plug or by checking your owner's manual. It's important not to use more voltage than necessary because too much power can cause damage.

While the look is not exactly "chic" and the price seems a little hefty, remember that this is more than just a simple book bag. For the money, you not only get plenty of storage (1850 cubic inches) but also a built in charging mechanism that would be worth much more if you purchased all those different chargers separately. Not to mention, the solar panels come in four different colors to add a little spice to the all black pack.

The bottom line? When you're on the go, this Backpack is a convenient, useful, and (most importantly) a sustainable way to stay connected.