So I made a trip out to the apple store again, and they were happy to exchange my busted iPod for a working one. Apparently it was so screwed up they couldn't even use it in target disk mode (note: to use an iPod in target disk mode you reset it by holding menu and play, then hold the fast-forward and rewind buttons at the same time). As an added bonus, the manager (who was actually the guy who sold me the iPod last night, amusingly enough) noticed that he had forgotten to take 10% off my iPod last night (since I had bought a copy of Panther at the same time, and they were having a special discount last night), so I actually got money back in addition to the new iPod.
And now I'm sitting here waiting for a monster-huge copy to complete so I can back up my home directory onto the iPod and do a clean reinstall of the OS. I've screwed around with this system enough that it's time to start from scratch, and I've wanted to partition the drive into 'Root' and 'Other Stuff' for a while, so I can more easily make this kind of transition in the future.