What format do you use besides mp3? Personally, I have already fallen in love with atrac3plus. I can increase the amount of music that I can put on my 32mb stick by 266% when converted to 48kbps(sounds little like 112kbps mp3). Second, is AAC. I don't like Windows Media Audio that much, because I can hear a strange noise in the background whenever I use that type of file.