I haven’t actually used Clutter for its main purpose (making little windows of all your album covers), but it works nicely as a smaller interface to iTunes. Not as small as the mini iTunes window, but it includes album art it grabs from Amazon.
The best part is the album-oriented browser. It puts compilations under “Compilations” in the artist section, rather than spewing them all over the place like iTunes and the iPod do.
previously: Pdf Manpages