Whenever you review a place from Google Places, you can share your experience with your Hotpot friends anywhere across Google. But since most of the people are actually using twitter to spread their word, it has become possible to share your reviews and critics with your followers, directly from your Android phone.
Another neat upgrade is that you can check in places with Google Latitude. You can show your friends what places you visited. Did you get an awesome sandwich or a bad beer? You won't need to lose time calling your friends anymore. You can just "ping" them on the map, if they have already checked in with Google latitude. This will send them an instant notification. As soon as they have seen your request, you will get a notification where on the map they are.
To use this feature, just download the new version of Google maps from HERE