Heatmap.js + D3.js with LandScan ambient population density data for the NYC area — fun.pic.twitter.com/cc7PG9ip5Q
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
@Casillic I have — not with great success. Ended up with very bloated, very slow, not entirely accurate models in the browser.