This script will add or subtract a half-star from the ratings of the selected tracks. Ratings with half-stars appear with "1/2" appended to their ratings (see the screenshot). I highly recommend attaching a keyboard shortcut to this script for faster access.
Also see Assign Half-Star Rating.
Perhaps Also of Interest...
downloaded 3m 30s ago
Removes leading and trailing space characters from chosen tags in selected tracks
downloaded 11m 25s ago
Create a playlist for each entry of a specified tag
downloaded 18m 15s ago
Delete empty playlists
downloaded 22m 1s ago
Perform search-and-replace on text in your choice of tags
downloaded 34m 13s ago
Display the width x height of selected track's artwork
downloaded 35m 20s ago
Remove iTunes tracks disassociated from files