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If you're not able to restore the device, you should use: http://support.apple.com/kb/HT1808
Using that article will erase everything on the device, so make sure you have a backup!
If you get specific error messages/codes in iTunes when updating/restoring, check this: http://support.apple.com/kb/ts3694 for causes and solutions
If any of those issues persist after restoring as new(without a backup!), you'll need to have it repaired, only a hardware repair can fix that. Schedule an appointment at the Genius bar of your local Retailstore or call AppleCare for solutions.
Now my iPhone 4s turned on after it wouldnt for a good half an hour. I will keep what you said in mind if it does it again. I am going to back it right now just in case!. (: