I find that if I leave music on all night, I don't sleep very good. It's funny, my roommate, if he plays music all night, will wake up in the middle of the night soaked with sweat. We've tested this (rather, I've accidently left music on all night and he's been soaked in sweat every time). The hold button on my old iPod nano won't work, so I never try to put it on hold anymore, since I'm scared it'll get stuck on hold. It's battery life is also pretty much shot, hah. Can't be bothered to spend money on another iPod, though.