One other point about iTunes, you can set iTunes to automatically play your mp3's after downloading. See iTunes section in your LW Prefs. iTunes will also make a copy of the mp3 into its own library. (You didn't say which mac OS you have.) There's also other Mac mp3 players & encoders around that can do things iTunes can't & do a better job at editing mp3 tags. But stick with iTunes as your main player. QuickTime can play almost all movies that have a QT icon (looks like a QT file. MPlayer / VLC will play the rest.)