Bicycle iPod dock

So here's my idea:

I'm restoring an old bike and there's a spot for a fake gas tank to go. I will build this tank, but one side will open up and hold within it an iPod dock. At least, I'd like it to. 

I'm thinking of using the pedals as a dynamo crank which would power the iPod and play music through speakers mounted on the handlebars. I've been doing a lot of research and it seems possible, however, I've not done something like this before and I was wondering if anyone would have any pointers on how to make this work well.

P.S. A separate USB port would be cool as well, so that a phone could be charged while riding the bike. 


Thanks for your suggestions!