iPod earbuds are just too large for me, and I can only use them for brief periods of time without having sore ears (how ridiculous does that sound :P). The fact that they're "free" sort of irritates me since I tend to continue using them despite this clear physiological indication that I should not.

Fortunately, my cat ate the last pair I had left from my Apple compulsion, so I was then forced to upgrade to something nicer on my ear canals. I switched to the upgraded versions of the regular apple earphones for work, and the in-ear earphones with mic for my iPhone. Neither of these were good for the gym (cord noise) so I got a cheaper pair of Sony earbuds for that purpose.