Which iPod sounds the best? It seems some folks take this question very seriously: Mark Heijlingers recently compared the frequency and impulse responses of two iPods using a pretty minimal setup of his mac's built-in line in and Fuzz Measure. Looking at the curves, I can only say I'd be shocked if someone using the included earbuds could hear the difference -- both are quite similar -- but he certainly makes the case for an audible difference in sound quality when using, say, a nice pair of headphones.
While I am glad there is interest in improving sound-quality, I doubt most consumers care that much. Truth be told, I don't care that much because when I'm using my iPod, it's usually in noisy environments anyway. But if it weren't for people who cared a lot, the sound quality would probably be a lot worse than it is now, so I certainly applaud the effort. Not to mention the fact that without audiophiles with iPods there would be no place on the market for wacky products like the vacuum-tube-based Music Cocoon MC4 by Roth Audio.
Thanks to Chris Pepper for bringing this to my attention.