Trendsmap is a new mash-up of Twitter, Google Maps, and What the Trend that maps out Twitter trends at the local level. Trendsmap goes so much farther than that, though. Clicking on any of the trends will bring up information on the volume of tweets for that word, a description of the trend (via What The Trend), and relevant multimedia and links. Trendsmap has a screencast that dives into some of its best features: