The source for the previous tweet? The always excellent Best Of MetaFilter: http://bestof.metafilter.com/
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
The source for the previous tweet? The always excellent Best Of MetaFilter: http://bestof.metafilter.com/