[Bleuachdu]

Did you try holding down the center button (assuming you have 4th gen or later) for 10 seconds?

Also, what happens when you try to plug in into your PC using either cable or the doc? Does iTunes recognize it?

Also, if the battery is dead, plug it into the wall using the firewire cable and leave it plugged in over night (or at least for 5+ hours) and try the above steps again. This happened to me once before after I updated the firmware. I fixed it using the wall plug-in method.