FYI, the iPod Classics will not work with this technique.
This method is only good for iPods with Video up to 5.5 Generation.
In other words, if you have video capabilities and Coverflow on your iPod (or nano) this trick won't work.
Apple changed the game so you can no longer access video through the headphone jack, you have to output it through the dock connector, and you have to pay Apple $50 for a cable that will work.
I love Apple, but I think this was very, very lame on their part.