I have a crank style radio that we use for camping. I like it but boy you have to do a lot of cranking.

Get generator lights! There is little drag and the lights are there when you want them. Cranking with your legs is sure easier than with your arm.

Also, just like the good feeling you get when you use human power instead of gas to get to work on your bike, using human power in place of buying batteries that don't last or need more energy to recharge is fun. Generators are very useful to power the bike's headlight. That said, they are limited to certain headlights and power levels. If you need 10w, it won't do.