Practical Solar Power for Travelers?

kalido asks: "When travelling with gadgets it can be a pain to keep the power flowing, especially in remote locations. Are there any practical methods to recharge batteries and devices when on the go? A bit of googling turns up the PowerFilm, PowerFlex and SolarRoll flexible solar panels. But I haven't seen any reviews anywhere. Have any of you used these or similar devices and how easy is it to use if attached to a pack, bike, jacket, etc.?"