Cast and Blast,
You just have to take 2 coconut halves, put sea water in them and some wire, stir the water and it will recharge the batteries for your CD player. Saw this on Gilligans Island and it seemed to work great! (As smart as that professor was you think he could have figured a way to patch the hole in the boat.)

I also want to throw in a second vote for some ZZ Top, probably the best concert I have ever seen. No fancy lights, big screens or fireworks, just some dudes playing their butts off for 2 hours!