This is a (mostly) Geektool customization. I have two clocks (other than the menubar's) going with Simple Floating Clock. Umm... and the album art is in one of the bubbles...
It's masked. Because a script pulls the current song's album art to an image on the hard drive, I can use Geektool to display that image. Then, I have a carefully placed mask image that is on a higher layer in Geektool that masks out the corners. It's a memory/processor hog though – not recommended.
Oh, 1) I don't remember. 2) I got rid of it because it slowed down my computer so much. (It was a script.) So you'll probably not want to use it. Sorry.