I've found that my Cambridge Soundworks speakers that I purchased with my old PC work on my ipod. They plug in the top of my ipod just like the earphones and are powered by it's own plug. It also has it's own volume adjuster on it. My question is, by using these speakers, could they be damaging my ipod. I'm guessing obviously no, but need to be sure.
Your ipod will be fine. Because the speakers have a separate power source, they only take data (ie sound) from your ipod. Turn the volume on your speakers right up and use the volume on your ipod as the main control.
Enjoy your music!