Nice things for you Mauro!, I have found it here:

Location-Aware Thumb Ratings

People have predicted very complex "augmented-reality" systems that might arise in the near future, when many folks will carry around location-aware devices. But how about a simple thumbs-up/thumbs-down rating system?

Here's how it might work: your device includes a green thumbs-up button and a red thumbs-down button, TiVo-remote style. As you move through the city, when you enter a favorite restaurant or club or cafe you click the "thumbs up" button. When you pass that restaurant where you got food poisoning or that stuffy overpriced bar, you click "thumbs down." And if you enter an especially wonderful place, you click "thumbs up" twice to give it two thumbs up.

The key: you don't have to interrupt your daily activities; just reach into your pocket and click one of two buttons whenever you think of it.

Each time you press the button, the device records your geographical location and the thumb rating. Soon you have a little database, a map that shows the spots around town that you love and the spots that you hate.

So what? So nothing, until people share their preference maps. Now you have a powerful concept. You can also form preference groups(...) For certain events you use time-sensitive preference maps with thumb-clicks that fade over time.

What I like here is the simplicity: you have two options: up or down. With a social rating, I don't think you need more. Or you can give a "neutral" rating like in the feature where you can rate +1/0/-1. But sometimes, allowing the neutral point is not so good, it depends upon what you want to do... or let's check in a Lickert Scale Manual...