Guys, if you have the ipod photo, I used to get the hard drive locking up , which would bring up the
www.apple.com/support/ipod screen.
WHen you try to start it up, put the ipod to your ear and listen to hear if the hard drive is stuck-ie if you can hear the drive repeating a clicking noise, then it is stuck.
If it does this, hit the ipod with an open hand (like a slap). No joke. This is for real. Slap it a couple of times and then try to restart it. If it doens't work the first time, try it again. SOmetimes it works first go, sometimes it takes a few, but eventually it does work.
It seems like the hardware inside is stuck for some reason and slapping it fixes the problem.
My ipod has locked up about 5 or 6 times and each time it has worked for me.
Give it a go. Don't pay apple to get it fixed. They probably do the same thing and charge you hundreds for it.
Good luck!