I have it set up in iTunes that the iPhone will sync and gather all music -- I don't really have that much -- and I thought that this is what was occurring, until this evening when I went to play a song by a particular artist and realized that the song and the artist were both missing from the iPhone, although they are present on my iPod and present in iTunes. I looked more carefully through everything and am wondering if the iPhone in fact is selective and kicks out anything that hasn't been played recently and actually establishes a specific limit of how many MB or GB of music it will accept? If so, that's fine, I can certainly take some time to pull together a playlist of my favorites specifically to ensure that they will show up on the iPhone, but I am surprised at this.....