On both my nano and iPhone, I have 557. I use my nano as back up for my music in case I go over on my phone, but most of the time I use my phone for music. I hardly ever use my nano. XD Both my phone and nano or 16 GB, but my phone takes a lot because of apps and other stuff. My nano on the other hand has a huge amount of room for maybe 1000 or more songs to put on it. So far, I only have a little more than half that, and its not even that full. XD
I tend to neglect my iPod nano a lot. :/ I really should listen to it more, but I just prefer my phone for some reason.