Taken from MizPee.com:
Do you ever find yourself desperately looking for a clean toilet in the city? MizPee finds the closest, cleanest toilets in your area. You can add and review toilets, get some cool deals in your area and challenge your knowledge of toilet trivia.
Has a rating system to rate the public restrooms in your area, and also has a "Wall of fame" and "Wall of shame" function.

Only listings for Major cities however, and none at all for certain states.