Not necessarily an essential application, but one that is pretty cool: CoverFlow allows you to browse your iTunes artwork in a really cool way (download it here). I like that you can right-click on an album that does not have cover art and then search for it on Amazon. Then it’s as easy as dragging the image from the Amazon search into the CoverFlow window, and that’s it…you have added cover art to CoverFlow. It would be really nice if this program would add the cover art to iTunes as well…maybe it will be added in a future version.
Update: The cover art feature is part of the new iTunes released this week. Apparently, Apple has bought Cover Flow from the company that created it. It is supposed to automatically download cover art, but when I tried it it had a hard time finding most of my music. I guess it depends on how you have your music labeled. In order to use the automatic download feature, you need to have an Apple ID, which is free.