http://www.freeplayenergy.com/product/companion
Freeplay gadgets get mentioned occasionally in other threads, but I would like to discuss this one in particular.
I highly recommend this little radio/flashlight/cellphone charger. In particular, the wind-up crank seems to be very efficient. I haven't personally tested the solar panel or the cellphone charger, but I'm impressed by the radio and LED flashlight. The whole radio is pocket-sized.
I find that it can be hard to find a place to put your hands while cranking that isn't on either the solar panel or the flashlight. Overall, though, I really like this radio.