those mp3 HD players have a lot of moving parts just like a computer's hard drive so you might have some problems. The small ones that run on media cards have no moving parts at all. I dunno, how intense is the exercise? If you have a way to stabalize an HD player it might work out, but I'm not 100% sure.
Most people live at the speed of life, I drink Mountain Dew!
i have a 10gb ipod. you never want to drop a HD mp3 player, BUT, get a good case for it, clip it on so it's secure and it wil be fine. Mine enver skips, sounds great, and actaully there are almost NO moving parts in it. The only time any part in my player moves is when it buffers. It's got 20 minute skip protection, I've never had an issue jogging w/ it.
I don't imagine jogging w/ an ipod would be such a good idea. I think it's a bit heavy for exercising (6.5 ounces). You're probably better off getting something that's made for using while doing a sports activity. Maybe an mp3 player like the RioSPORT - I just started doing research on this so I don't know of any other sports mp3 players "yet" http://www.sonicblue.com/audio/rio/s35s.asp
I wasn't able to find anything specifically on whether you "can" exercise w/ an ipod but I'm guessing it's not wise. Would you ever jog around with your laptop, your computers HD, or even your pda even if they were safely secured in some sort of backpack?