Twaps is a combination of Twitter and Google Maps. This tool allows you to keep track of what people are talking about in a specific area or location. It is very easy and simple to use, you can either use the search box to search for what is trending in Twitter in a certain place or you can share your place with the app and it will automatically provide you with the tweets being shared around your location in real time.
Twitterfall also integrates Google Maps and is basically " a map visualisation of real-time geolocated tweets being made around the world."This is how it works: when you fist access it you will see map markers falling down all over the map. Those markers represent tweets that are being shared in real time in places where the markers fall down. In this way you will have an idea of the Twitter activity all around the world.
Courtesy of Google Maps Mania