Google’s released Hotspot that connects to its Google Places. When someone rates a restaurant, the site recommends other places in the same city – say San Francisco – that has similar food at a similar quality. The social piece involves the rating of friends for venues, which can be shared and viewed whenever the users is on Google Maps for Places for Android.
You rate places and add friends using the Hotpot rating app. Also, when you’re visiting places, you can continue rating on the go from Mobile maps on Android.