Neat - Thanks Doitsu!
I fiddled with your code and got it to show the left half of the star black with the right half missing if anyone is interested. (edit) I also changed the color from white to transparent so it'll work on any background color.
(edit-edit) You can change how much of the star is visible by changing the "width" (.25em for 1/4 star, .75em for 3/4 star)