Like tech guy said, you can always just hold down the top and middle buttons together for around 8 seconds (thats what my manuals all say) and that should restart it, thats happened to mine before.
I would say you should jsut get a new ipod soon anyway, because its going to die eventually and if you get a new one you can use your one for rougher things like taking it to work (if you have a rough job) or riding a bike or something without worrying about breaking it. Thats what I did, until the screen of my ipod cracked. That kinda annoyed me :P