I'm pretty sure it isn't overheating. But I just want to double check. I jailbreaked my iPod Touch with 2.2.1 firmware. Then everytime I played an app the bottom of the iPod would get very warm. Not too hot to touch, but really hot. Yesterday, I gave it to my friend to play pool on, when I got it back my home button wouldn't work. Then when I got home my battery was dead, when it was about 80% about 4 or 5 hours before. So, since it was a thethered jailbreak and my iPod wouldn't pick up in USB mode, I had to DFU it and restore it. And it still gets warm, I only had the flashlight app on, the ebay app then the remote app on for about 20 seconds collectively, and it was getting very warm. Note: it was charging at the time.