Try reading through this and see if it helps...
http://docs.info.apple.com/article.html?artnum=61711
The fact that it won't connect to another computer either leads me to believe it may be a cable problem. Do you know anyone else with an iPod whose USB cable you could borrow or test it on their computer with their cable? You want it to say Do Not Disconnect. If that doesn't workand you've read through the above link then post back 🙂
btabz