iTunes 6.0.2 will now display half-star ratings -- that is, songs with a rating of 10 will display ½, and a rating of 30 will display *½, and so on, as seen at right. Note however, that this is broken, in the sense that a song with a rating of 31 will show up as a one-star song, not a 1.5 stars song.
To rate a song as a half-starred value, you can use a simple AppleScript as seen below, or one of the many available rating systems out there. Or here's a one-line AppleScript to set the rating for the currently-playing song to 1.5 stars:
tell application "itunes" to set rating of current track to 30
Modify as needed for the other values.
[robg adds: One such rating system is Add-Subtract A Half Star from Doug's AppleScripts for iTunes.]

