If anyone else out there is irritated that some MP3 stores like Amazon MP3 Capitalize Every Word In Song Titles, Even Small Ones Like ‘The’, you may enjoy this AppleScript.
That’s Proper English Title Capitalization by Cantus Vetustus, which is excellent except for the fact that the list of ‘small words’ that get uncapitalized is a bit incomplete. So I merely replaced the list with that of John Gruber’s Title Case (which gets its list from the New York Times Style Manual).
To install the script on a Mac (no luck for Windows users) drop the file into /[username]/Library/iTunes/Scripts (and if that folder doesn’t exist, make a new one). Then a little paper scroll icon with the new option inside should appear in your iTunes menu bar.