There are plenty of hints on this site that use the defaults command to change preferences or settings that are unavailable via the GUI. These are fine to use for isolated changes, but there are some applications where you might want to change a number of settings.
iTunes is one of these. Over the years, Apple has removed a number of options from iTunes; at least from its menus and preferences. Many of these options remain, but are hidden.
Doug Adams' free Change Hidden iTunes Preferences is an applet that lets you change a number of settings. I use it to make sure that when I rip CDs, track numbers are added to the file names; to hide Ping buttons; and to hide the arrow buttons that display next to tracks. Other options it offers are the ability to turn on half-stars for ratings (useful for smart playlists), showing the "Libary" playlist at the top level of the iTunes source list, and to create playlists for new purchases such as albums.
This is a simple GUI tool that allows you to check some buttons and click Apply. So if you want to make changes to some of these hidden settings, check out this applet.
Mac OS X Hints