I don't think this was in Jag, but the Panther finder seems to remember the last volume setting when previewing mp3's and etc. Not that big a hint, but certainly handy for those of us who were annoyed at the previous default, which was max volume
[robg adds: After being shocked more than once by very loud sounds when previewing multiple movies, I can attest that this is certainly a new (and much improved!) behavior in Panther.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031027223410118