Just noticed a long awaited feature in iTunes, that albums now have an "album rating" that is automatically calculated (presumably some kind of average, perhaps weighted by track length?) and displayed for each album, and it has been added as a smart playlist rule criteria. That will make it much easier to make smart playlists for, oh, say some iPod that only has 16Gb of flash.

So now all I have to do is make separate "album rating" and "track rating" playlists for each rating, and pick the correct one depending on whether I want to listen to albums or tracks. Now, if only you could tag a playlist with a shuffle mode, it would save a lot of fiddling about in the settings menu!