5 green gadgets to keep you charged on summer vacation

Admit it, you are as addicted to your mobile phone, personal digital assistant or MP3 as the next person. Even when you're enjoying the great outdoors. Wireless coverage continues to improve in the most remote locations, but how can you make sure your gadget is juiced up in as eco-friendly a fashion as possible? Quick answer: Your mobile device can have as much fun in the sun as you deserve yourself.

Gallery: Green gadgets to keep you charged this summer

Last week, I wrote about a $150 item from Tremont Electric that uses your body movement to give you a charge. The nPower PEG (below) was slated to begin shipping this month in the United States.

But this is by no means your only option for staying charged on the go. In no particular order, here are five pieces of solar technology that could give you an extra power boost in the great outdoors if you're the kind of person who enjoys nature but still can't live without your gadgets. This list is definitely not all-inclusive, but it represents many of the innovative designs that have hit the market in the last 6 to 12 months.

1. The NEW Solio Classic-i

The Solio Classic-i from Better Energy Systems (a company that got its start in London) is distinguished by the fact that its predecessor designs have generated sales of more than 1 million units so far. The device is priced at $79.95; it opens up (ala the photo on the left) to capture the best solar angle. There are all sorts of tips you can choose, and the company claims the charger works with more than 3,200 different mobile devices. For those who are truly techie, Solio works in a 5-6V, 800mA output range. It actually will hold its charge for up to a year.

2. The Freeloader Series

The folks at Solar Technology love trumpeting the fact that the Freeloader solar charger series, which I first featured back in April, has been used on every continent on the planet.

The series is priced according to capacity. The PICO model (sunning on the raft to the right) starts around $30 and takes about 30 minutes to charge something with its 75mA solar panel. The Pro edition can handle pretty much any sort of devices including an array of smart phones and mobile gaming devices. It runs around $120. One caveat is that the parent company ships from Europe, so if the Icelandic volcano acts up again, you might end up waiting for your order.

3. U-Powered

For $50, you can buy the new U-Powered bundle from KIWI Choice, which hails from Ottawa, Ontario, Canada.

As you can see, the kit has the same fan-like solar panel design as the Solio, and it has a capacity of 2000 mAh. U-Powered comes with 11 different connectors, and KIWI Choice says it's good for approximately 1,000 charges.

4. i-Sol Plus from Silicon Solar

This is one of three mobile charger products from Silicon Solar, which creates a wide range of other solar technologies -- everything from solar panels for your roof to kits for your build-it-yourself electric car.

The device pictured to the right is the iSol Plus, which comes with three different DC adapter output settings (5.5v, 7.5v and 9.5 v). It takes 10 to 20 hours to charge up iSol with the sun (2 to 4 hours using its USB adapter). The series is priced between $30 and $40, depending on the gadget you are considering.

5. Surge

The Surge from Novothink (at left below) represents one of the best-known "sleeve" type solar chargers that is available for Apple gadgets.

The company provides an iPhone applet so that you can figure out which of the models that you should buy, based on your current mobile phone usage patterns. The iPhone edition costs about $80. The one-not-so-great thing about these sleeve designs is that they generally can't work from generation to generation of the Apple iPhone designs.

So, maybe you can send yours to me, Mom, when you get your iPhone 4 later this month?