The iTunes Music Store offers many CD covers in 600x600 high quality jpgs. It would be awesome if Mp3tag could download them.
I found a couple of websites that can do it, so I thought it would be possible for Florian to add this.
Why? Because a lot of times covers can't be found with the current methods. Also, because these covers are higher quality than what I've seen before. Take a look for yourself.
The second one explains a bit how to do it (also in the comments), hopefully it'll be a starting point for Florian.