Eton. The solar-power speaker system can stream music wirelessly from your Bluetooth devices, bumping it in style through two full-range speaker drivers. The system is powered by a solar panel (though you can also power it the old fashioned wired way, when the sun's nowhere in sight), but don't worry about reading the screen in the sunshine -- the Rukus has an e-ink display, which also helps the thing conserve a fair amount of power. Eton also says that the player is "virtually indestructible," a claim we're sure some folks will want to put to the test when it drops in Q2 for $150.
Update: Check out our hands-on here!