Think magazine's blog is officially out of hiatus, so here goes. I recently purchased a new laptop that I desperately needed for business and well as pleasure. Now I understand that laptops tend to last around 2hrs without tradional energy, and mine is no exception, but I felt 2hrs may not be enough time in some circumstances.
The Brunton solar roll flexible solar panel can be used for computers, cameras and mobile phones. It comes with a car and a multi linking cable which should allow you to power up any of your rechargable devices. On their site it did not list MP3 players but I would suggest sending an email to the company.
The solar roll is available in three different sizes varying in price. Works in low lighting and takes up very little room. Just think you'll never run out of energy...ever.