Totally awesome. Quite frankly, I'm mad I didn't get to it first as I'm also obsessed with these grades.

I would suggest maybe changing the tag-line on your front page to "there are no more excuses for the unknown reasons behind your favorite restaurant's grade, but that's just me.

Also, on Firefox 11 for Windows XP I'm having a hard time even reading that text. You might want to consider adding a little weight to it as it's quite badly aliased.