Is it a white screen? Have you tried hard reset, soft reset, DFU mode, and recovery mode? If it continues to be stuck you can take it in to the apple store and they can do something about that.
I read this might help: "Press and hold the home button, then the up-volume button, then the sleep/power button (so all three buttons are now pressed and held) --- it takes a while, but the white screen will go away and then after another 10 seconds or so (still holding btw!) the apple logo will come up, release the buttons and then wait, it'll boot normally again in a minute or two."