Curator is an application that can be used to download artwork for your iTunes artists and albums. The artwork can be downloaded from either iTunes or Amazon and then transferred to the iTunes app. The graphical user interface consists of two panes. The one on the right has a list of all your artists. When you click on one of them, you will see how many songs you have for that artist, their duration and how much space they use on your hard drive. There are two circles next to each artist. Artist with red circles don't have any artwork and the ones with green circles already have artwork. You can download missing artwork by clicking on the "Get Artwork" button at the top of the screen, or by right clicking on the artist's name.
By default, Curator chooses where to download content from, but you can select the artwork provider if you use the right-click mode.
Unfortunately, in my testing, I was unable to get the application to download artwork. Whenever I clicked on the download button, a progress bar was shown at the bottom, but no artwork was shown. I copied artwork to iTunes to see if maybe Curator had problems displaying it, but nothing was copied. There were no errors, so I can't say for sure what the problem was.