[affgrff2]

I think this is cool and hope your location gets the HN effect today aka real world ddos :)

Just to dump an idea: Maybe instead of using a scale based rating, you could experiment with something that has not a clear maximum value to prevent the all 5-star rating effect described by others. The only thing that directly comes to my mind would be a button, that the user has to hold until the time matches the perceived rating.