error formatting iPod

I attempted to restore my iPod, but a message came up that said, "There was an error formatting the iPod." It didn't say anything about a disk write error or anything like that; that message was all that came up. I disconnected it and plugged it into AC, and now my iBook doesn't recognize the iPod. It will bring it up in disk utility, but it says the iPod is unreadable. It also comes up in iPod Updater, but the restore still won't work. And its format is "Unknown," obviously. I'm just not sure how to re-format it...