I'm with rumpelstiltskin on this. Being persuaded to not eat somewhere after getting there (maybe you made a reservation, even) and then having to make the decision to leave and find another restaurant is a total pain in the ass. Especially during, say, dinner time when the whole area is trying to eat as well. Maybe you went way out of your way to get to that restaurant. Maybe you told your date where you were going and she got all excited about it, now you're stuck eating there -- health code violations or not.

That said, I think the idea of this service is totally cool. It just needs the ability to check before getting to a restaurant. That will complete the service IMO.