Just came across this review of two green media players from David Pogue of the NY Times.
The first device reviewed is the Motion Street eMotion Solar, which can play mp3's, video, and also has a couple of classic Nintendo games to play.
And it's completely solar powered.
In fact, with an adapter, the integrated solar panels can be used to charge a phone, or a USB chargeable device, which might eliminate the need to carry around a separate solar charger.
The second media player reviewed is the Baylis Eco-Media Player, named after Trevor Baylis, an Eco-Conscious inventor.
The Eco-Media Player is cranked for power (1 minute gives you 40 minutes of play). It's kind of like the swiss army knife of media players: it's a flashlight, music and video player, audio recorder, phone charger, mass storage device, picture viewer, and an FM radio, among other things.
It seems like, if you were going to choose a media player to bring camping, or keep something in your bag for emergencies, these two green media players would beat an iPod any day.