I am pretty sure that isn't at all possible. In fact, I am almost 100% sure that doing that isn't possible (on the Apple firmware). Now, maybe with iPod Linux is could be done, but even then I am skeptical.
there is a program called podtype which allows u make notes using the on-the-go playlist feature. The people who created it made songs half a second long and made their names A, B, C etc.
Here's the link: podtype