Thomas built a steam powered iPod generator. From Jake von Slatt's Steampunk Workshop:
I coupled a Lego Technic Motor to a Jensen #75 steam engine to make a crude generator. From there I built a 5V regulator circuit and soldered in a female USB connection to power any USB device. Since I wanted to use it to charge my iPod, I put in a diode and a .5 amp fuse to provide some circuit protection. Attached are some pictures of it and here are some links to videos of it in action. Unfortunately you can't see the charge light on the ipod, But as you can hear, the iPod really loads the engine. I was somewhat surprise it could hack it.
What a cool idea. Just think if they could scale up this idea and use steam to generate electricity for entire cities!