I was listening to music in iTunes using Grid view, and as I was rating my individual songs within one album, I noticed a row of dots under the actual album that actually allow you to rate the album as a whole -- just click and drag on the dots.
I am not certain if this is new, but I guess I never noticed it and wanted to pass it along in case someone else hadn't noticed it.
[robg adds: I believe this is actually list view with album art showing. In my grid view, I don't see any way to rate an album without using the contextual menu option.]

