Twitter launches local trends
Twitter had this trending topics section from the beginning itself it seems. Using this trending topics we can get the topics which are widely discussed in twitter. It can be strings with #tags or just a phrase that is widely used among the tweets of twitter users. But till now this section showed the trending topics from the whole world.
Twitter has launched their location aware service a few months back. Now they are coming up with an idea local trends. But I say this came a little bit late. anyway better late than never right? 
Now there is an option for changing the trending location to any country. You can see it just above the trends. the list of countries are being added to their database.
Twitter said about this in their official blog,
Local Trends will allow you to learn more about the nuances in our world and discover even more relevant topics that might matter to you. We’ll be improving this feature over time to provide more locations, languages, and data through our API.
