Inhabitat Earth Day special: how to go off-grid with your gadgets

The Week in Green is a new item from our friends at Inhabitat, recapping the week's most interesting green developments and clean tech news for us. Today is Earth Day, so we're happy to have Inhabitat contributing this How-to guide for us.

Earth Day isn't just a time for Birkenstock-clad hippies to preach about living off the land. It's also an opportunity to stop and think about some of the easy ways we can lighten our load on the planet, and disconnect from the tether of the electrical outlet and the office cubicle and enjoy the great outdoors. For gadget lovers, that means going off the grid -- whether with mobile solar, wind, hand crank chargers, or hydroelectric power. Below, take a look at some of our favorite off-the-grid gadgets.

This handy mono-crystalline cell-covered backpack from Voltaic Systems offers up 4 watts of power at full charge. One hour in the sun generates 3 hours of iPod play time or 1.5 hours of cell phone talk time. Want to use the backpack charger at night? No problem. The backpack also comes with a removable battery back either stores excess energy from the sun or charge via USB cable. The Voltaic Backpack retails for $249.

The tiny HYmini charger is your own personal wind turbine -- just hook it up to your camera, cell phone, or iPod while you're walking through the wind and watch the charger go. A 6 watt rechargeable powerbank stores excess energy for later. For days when there isn't any wind, hook up the HYmini to solar panels or an electrical outlet. The HYmini Deluxe retails for $75.

You're stuck in the woods with a dead flashlight. What do you do? Whip out the BoGo Light, a powerful solar-powered flashlight that lasts 20 years and can shine for 5 hours at a time. There are plenty of other solar-powered flashlights on the market, but the BoGo Light comes with a feel-good bonus: for every flashlight that you buy, one goes to people in developing countries that lack reliable access to electricity. The BoGo costs $59.99.

This massive backpack hydroelectric generator from Bourne Energy may solicit some strange looks while you're lugging it down the street, but the three foot-long, 30 pound prototype device is nothing if not useful. A single self-contained unit can generate 500 watts of power from any stream of water. When combined, multiple backpack units can generate up to 30 kW. No word on a potential release date for the $3,000 generator, but the military is supposedly interested.

The next time you go camping, consider bringing along the LightCap 300, a combination BPA-free one-liter water bottle, solar-powered lantern, and waterproof container. The bottle features 4 ultra-bright LEDs along with a red LED nightlight. At just $29.95, this multipurpose device is definitely worth shelling out for.

Little-known fact: coffee-makers suck up lots of energy, even when they're not in use. So why not get rid of your electricity-powered coffee-maker altogether? Presso, a manually-operated espresso maker that combines hot water from a kettle, finely ground coffee, and mechanical leverage to produce a quality cup of espresso. The Presso retails for $150 in the U.S.

When it comes to being off the grid, solar and wind are not the only options. Hand-cranked chargers offer the independence of relying on something you can easily control (your own man or womanpower), and the Freeplay Companion is a great option. It's a radio and flashlight all in one, meaning that you get two valuable tools. Plus it has the option to use solar if you're feeling lazy. The Freeplay Companion retails for $32.

Sure, it's important for off-grid gadgets to perform, but looking good doesn't hurt either! Case in point: SolarSurge iPod cases. These sleek accessories are the first ever to be certified by Apple and can harness the sun's rays to extend audio playback by 20 hours and 3G talk time by 4 hours. SolarSurge cases retail from $69.95 - $79.95.

We all know that kerosene smells awful, but did you know that it's also very expensive and highly toxic? And yet so many people in developing nations still need to use the harmful substance just to light their ways at night. The Solar Pebble is changing all that and is a lightweight, inexpensive gadget that captures the Sun's rays during the day to provide light or power small electronics. It isn't out yet, but look for it here in June 2010.