No. 4: PowerFilm USB + AA Solar Panel Charger

A portable solar charger is your life source when traveling abroad. Not only can you charge your cellphone and MP3 player, but the versatile PowerFilm Solar Panel Charger, available from for $99.99, can also charge your AA batteries from your camera. It can charge AA batteries in four hours (in full sun).

Light (it weighs only 49 ounces) and foldable (it folds up to about the size of a men's large wallet), this solar charger can travel with you anywhere, so when you're on a day hike, let it soak in the sun's rays during your lunchtime picnic.

You can even charge your devices at night through the USB port because two included rechargeable batteries act as storage devices for the energy absorbed by the solar panels during the day.

Day or night, you'll be powered up with the PowerFilm Solar Panel Charger.