I have a soundtrack album on which the tracks do not follow the chronology of the movie they came from. It was a simple task to re-order the songs in a playlist. But, when I exported the songs to a folder, they were exported in the original order instead of the order defined in the playlist.
So I changed the Track Number tags in the Song Info window, and discovered a way to speed up the process. Command-N and Command-P are keyboard shortcuts for the Next and Previous buttons. When used, these shortcuts also highlight in the next song the text field you edited in the last song. Now that you know, you'll never have to click again when renaming or reordering songs.
[Editor's note: Although I don't usually run hints for things that can be found in menu items, these are a bit buried and some of you may have missed them. To display these (and all other keyboard shortcuts) in iTunes, just select Help -> Keyboard Shortcuts.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030117061901144