O'Reilly's books on mining social data (and Twitter specifically) look interesting: http://oreil.ly/eFgtx0
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
O'Reilly's books on mining social data (and Twitter specifically) look interesting: http://oreil.ly/eFgtx0